When playing in Bloodbath mode in Strife, monsters such as acolyte open fire practically as soon as they see you and then will not do anything else but shoot at you until you hide behind cover. However, in vanilla, they do move around quite a lot, making the start of the game a lot more survivable, as demonstrated here by Belial:
Or here by someone else:
You'll notice that despite the acolytes moving and shooting faster than they do in ZDoom (their states lack the fast flag, as shown here), they're quite easier to kill without getting shredded because they waste a lot of time moving around. In ZDoom, they don't.