I enabled Mercs added a Tank(warrior) merc and spawned a warrior bot, same race etc and made a little video of what I am seeing:
https://youtu.be/C_pK_ORv41M
The encoding is terrible but if you watch the bot, it jitters, but the merc seems pretty good.
This is with both pathfinding and the extra pos updates enabled. pathing is understandable, but I can't understand the difference. They can join groups, fight, cast spells and have very similar movement code.
Does the client really handle bots that differently? Are you seeing something similar or is something wrong on my end?
If you want a more clear video I can provide the source mp4, but I think you can see what I am trying to describe.
EDIT: Link updated to try to avoid terrible ads for those that don't have ad-blockers