I will be... synthetic on this. Going to hear your feedback in order to elaborate a new timeline for EVIL DEAD.
THE EVIL DEAD/EVIL DEAD II
The prologue of ED2 is a false memory. Ash was traumatized.
The cabin's interior assumed the aspect of Knowby Cabin 2, the one located in the AVED Season 2 parallel universe. So, the original cabin's interior was TED, then it turned into the one you see on ED2. Magic. Ash just didn't care, he was busy to survive.
EVIL DEAD II/ARMY
The ending of ED2 truly happened. The crowd of knights were NOT made of Arthur's men, but soldiers related to Henry The Red. Arthur came in, and there was a big battle/war where Ash was taken as prisoner. Ash had been a slave for months. They cut his white hair streak.
So that's a possible way to connect ED2 and ARMY without deleting the ending of ED2.
AVED SEASON 2
The Evil Dead timeline is a closed loop.
In Episode 9, they travel to "the" 1982 of a parallel universe, where the cabin is different. Those events always happened in both the universes, they are closed loops. When Cabin 2 explodes, they are magically transported to their original universe, and the "explosion" transfers itself to Cabin 1 in 2016. That's it.