7. Enemy Counter-Attack Markers
The biggest and most obvious omission from combat in general is an easily-seen enemy counter-markers that would let you know someone was about to get the drop on you, allowing for a swift and brutal counter to keep them all in step. In Unity they reduced the window for countering to be very small, alongside having the only visual accompaniment being a portion of the enemy's life bar itself changing colour; something that's very hard to see when you're in the middle of a scuffle. This isn't a question of game mechanics and refined difficulty, instead it's just deliberately obfuscating elements of the game's HUD for the sake of making encounters near-impossible, forcing a stealth approach that's equally cumbersome. The simple fact being; if an enemy off-screen wants to attack you'll never see the counter window and be taken out regardless. The AC games used to be elegant power-fantasies, and part of that came with the balance of knowing you could handle yourself in a fight if things went sour. Refine the combat, sure, but don't make any enemy showdown a downright frustrating mess of getting cheap-shotted because you couldn't tell which direction you were supposed to face.