Looking at those screenshots - that behemoth has completely clipped into some rubble, there. That would completely ruin him of course, but also, I can't cause that directly.
There aren't any changes that I'm aware of that would cause a fight to start any sooner than before.
Another thing - I deliberately coded the behemoth behavioral change to only kick in if the behemoth is in direct combat with the player and his followers. The code that makes this work is:
if target != player MQ01BehemothREF.pushActorAway Target 10 if target.getplayerteammate == 1 target.scaonactor target.stopcombat endif else
It's sick-simple but it creates exactly the behavior I wanted.
I think on my first playthrough ever (vanilla), I arrived there and the behemoth was already out and his helpers were already dead. I'm not sure what's up with it ...
I'm not sure if Foes Reworked did something to contribute to the scene not working right. I could open up that area and take a close look maybe - - - it could be that there's issues with it just, as it is, not so much Foes Reworked causing it.