anet has done something really weird recently to the henchmen AI. You send your team out to kill a group. The team kills the target, and then comes running back to you instead of killing the other 5 enemies standing right next to them.
Also, while doing the To Tankahki Temple quest, mhenlo just runs ahead and dies in 1 big spike. If you try to go ahead of him to prevent this, then he will aggro the afflicted group that you avoided and get spiked.
FIX IT, NOW! And don't EVER touch the henchmen AI again. Leave them alone. They worked just fine, quit messing with them! Leave them alone and address the REAL problems in gw.
Bring back the old henchmen AI.
Dahl
dargon
They haven't made any changes lately. Call a target, your henchmen will beat on it and if a different mob smacks them when they are done, they'll do it again, just don't be too far away from them, without a flag, they simply think you're running away and they want to live too 
As for To Tanakhi, I just did it this past weekend without issue, stay with Mhenlo instead of trying to clear the path and you can protect him, the afflicted you're talking about have a patrol that can intersect with his path, this is how it's been since day 1.

As for To Tanakhi, I just did it this past weekend without issue, stay with Mhenlo instead of trying to clear the path and you can protect him, the afflicted you're talking about have a patrol that can intersect with his path, this is how it's been since day 1.
II Mr Sinister II
AI seems the same for me too. Alesia (Monk) still runs to the front line and attacks like she's a tank, Stephan still runs in like a noob drawing all in to there doom no matter how many times you click the ground or post your flag, its no biggie you just need to prep more & remember henchies have there own aggro circle too.

Praetor
You can flag henchmen. Not using the flag commands is your own fault, not a problem with the AI.
Each AI update has improved the quality a little bit each time. No need to go backwards.
/notsigned
Each AI update has improved the quality a little bit each time. No need to go backwards.
/notsigned