I have to say that I have noticed this too. Before Gwen came out, I spent alot of time skill hunting with just H+H, and then i started Gwen using the same team setup.
With one of the updates last week in particular, the instances of caster heros running to melee range to cast something like meteor shower have increased ten fold.
They are also unresponsive, and i have noticed the same thing about refusing to move when they are in range of simbiosis - maybe they dont want to lose the health boost :P
They do also refuse to break aggro, even if i flag them back from battle, they stand there casting spells and dying instead of following the flag.
Something else i noticed is that Master randomly refuses to follow my target calls when he has minions - he just stands there with them all around him while i have to fight on my own :/
Hero and hench AI is seriously broken
Another thing i almost forgot, neither monk hench or hero hench will heal a party member if only one of your party is taking damage - making it kinda hard to tank.
I only notice this when LoD is the elite - even though they have orison and other such spells on their bar.
They also seem to have stopped running out of aoe damage - ive lost count the number of times they've stood in maelstrom's, and al you can hear is; click, click, click, click, argh!, dead.
They need fixing to be honest.
