So who'd win a MCU Royal Rumble?

Ok, let's address your concerns 1 by 1. 

1. Teams won't work - if you've watched previous Royal Rumbles, you'll know that team-ups absolutely happen. There are even times when the 2 guys in the ring refuse to fight each other because they're friends and simply wait for the next person to come in at which point they gang up on him. It will also mean that strong contenders who can last long have a higher chance of forming their teams as they can survive long enough to team up. In which case, again, the Revengers have the advantage in that majority of the strongest characters are part of their team. It's not for certain, sure, but they have the strongest case for being able to team up. Whatever criticisms you have against Loki and Hulk being able to practice team-work is contradicted by the fact that they've actually shown team work on screen. 

2. Vision can still density shift and phase despite getting electrocuted - again, please prove this. You keep claiming stuff without backing it up with proof. Vision was caught in the electricity trap that Hawkeye set. He couldn't phase through the floor to escape from it, couldn't make himself heavy enough to break through the floor to escape from it. So please provide proof. Yes, Vision can still blast with the mind stone. So? Ironman can still blast with his weapons, Thor can still blast lightning, Carol can still blast with her powers, but all of them have the advantage of being able to move. Vision being immobile and relegated to simply using his mind stone blasts would be at a severe disadvantage against the other heavy hitters in this match and would be easily knocked out of the ring. 

3. Sorcerers can create shields and weapons and platforms - let me ask you: Who were the strongest enemies that they fought off with those weapons? I certainly don't recall their weapons being that effective against opponents on the strength level of Hulk or Vision or Carol. Yes they can generate chains but other than Dr. Strange, I don't recall them generating chains that can hold down extremely strong opponents. Their shields and platforms are definitely useful, and that's why I was thinking they're some of the last ones to get eliminated. But in the end they just haven't shown enough firepower to be able to push out the strongest players here, especially if teams start forming. 

4. You're mentioning how IM now has his super-updated suit. I agree. But don't forget that Thor has now unlocked his full thundergod powers and also carries around Stormbreaker. You really think they can snipe beings who've been proven to be proof against almost every human-made weapon? Remember the last time Ironman blasted Thor in the face point-blank with his repulsor? Nothing happened. Thor didn't even get a rash. Obviously Ironman has gotten stronger since then but then so did Thor. 

5. I didn't "spin a story". I pointed out who the most powerful players are in this match and pointed out who would win IF we didn't spin a story. Now IF you want to go ahead and spin a story WWE-Style then yeah, you could definitely make anyone a winner to fit the narrative and I'll respect your opinion on that. After all, you're the one who replied and criticized my post. All I'm doing is trying to defend my stance. I have absolutely no problem with your no-legs winner story. 

1: Yes but unless the Revengers form from the very start, and even then to control Hulk enough to team up you will likely need Valkyrie and Thor to start off together, then hope they can stay until Hulk gets there, and depending on the variation on Hulk this will only go so far, Avengers Hulk may just knock Thor out because well he's kind of a dick, Hulk not Thor, Ragnarok Hulk could do it by being childish and simply throwing someone to Thor at an inopportune time, let alone them starting to brawl because Thor or Hulk get pissed at one another, and again Hulk's loyalty can easily shift with Widow turning up.

Plus people can only be eliminated once entered the ring, ranged strikers can attack and throw those powerhouses out or wait for others to gang up on them without entering meaning they also cannot be eliminated even if Thor starts throwing lightning, let alone if CM comes out before the full Revengers team can get in place to fight her off, team ups can work but not huge group efforts like you suggest long term, Loki's traitorousness also plays a factor, only a handful of people are a challenge to him, half of which are on his own team, he's more likely to eliminate or allow them to be eliminated once the few others are taken out, if he even waits that long as he may get cocky and underestimate Vision or Wanda.

2: Density shifting is tied to the mind stone, the mind stone he can use whilst being electrocuted, we saw in CW that Wanda used her powers to activate the stone to force him to phase as to release Clint from Vision's grip, so you need to prove this doesn't work, evidence shows the mind stone works even during electrocution, no evidence to suggest it doesn't, just because he doesn't do as you say in the CW scene doesn't mean it isn't possible, he also didn't blast the arrow's straight away he clearly thought about the best way out of the situation, which was eliminate the weapons rather than just escape them.

And again he is only stuck whilst being shocked, so you have to assume Thor knows this and doesn't drop his guard, and knows to grab vision from behind so he cannot be blasted, imo more likely Vision will outthink Thor and at an opportune time blast him there by freeing himself and quickly eliminating Thor if the two get into a scuffle, let alone the density shifting side of things.

3: Strange used them to fight Thanos and held his own for a fair bit against him whilst he was wielding 5 of the Infinity Stones, Strange maybe the sorcerer supreme that doesn't mean only he has effective use of the magics on hand, and again yes they wont be able to over power the likes of the Revengers but power doesn't defy gravity they can actually use their shields to build platforms for them to get elevation and then lasso the likes of Thor around the waist and hoist them into the air and swung out of the ring, if they catch Thor off guard his power wont really prevent this, only in a straight up tug of war does that help, Hulk is immune to this due to his sheer weight however.

Yes Thor & Hulk will likely smash through their shields if used to simply block their blows my point is them using them creatively to throw them off balance and creating a slide to roll them out of the ring, creative thinking is what I am using which I believe they would to, where as you are like Thor & Hulk only thinking about brute strength, what happens to those deadly shockwave attacks when mid air a platform appears just under the feet of Thor or Hulk and not their fists or hammer? they lose balance is my guess and fall which then lends itself to the slide approach I said.

4: Yes but I am not talking about it damaging Thor, I am talking about the concussive force knocking him back, Tony sent Thor flying in Avengers, but he didn't leave a mark on him, it isn't about hurting Thor but sending him flying, the faster and more powerful armour will knock Thor flying even further this time, and Thor as well as Hulk tend to like taking big jumps such as to deliver shockwave blasts, taking to the air opens Thor up for Tony's and other's big blasts which will be pointed upwards causing more distance for Thor to be sent flying, without the ability to fly with his hammers to stop himself Thor would be victim of physics, and with Tony doing the calculating the physics will likely send Thor out of the ring.

5: You absolutely did spin a story, so have I, so has anyone putting forth a perceived course of events, you story is the teams manage to all get together then start fighting and the Revengers stay amicable enough to not self destruct mid match, I spun mine based on the thinking powerhouses will take each other out leaving the stealthier competitors to last till the end, yours is based on what you perceive the powers to be, mine is based on the strategic play I think they would incorporate, both are stories however which benefit the approach we each think would win out.

Discounting the possibility of the Revengers imploding I think your scenario works in a Tournament Of Power setting like in Dragon Ball Super, but a Royal Rumble is very different, which is my whole point that and you nerfed the hell out of the Sorcerers darn you, but as per usual we kind of went off on a whole load of other points, it was fun.