Terry's rogue gallery desperately needed fleshing out, I agree there. That being said, I can only give them props for trying desperately not to just "Copy + Paste" Bruce's rogue gallery into the future.
I did get really tired of Inque and the Royal Flush Gang. And Spellblinder, Shriek, and Stalker had fairly weak follow ups.
Doctor Chimera, Arsenal, Terminal...I wish we'd gotten more with them.
Though I do want to say part of the problem with Terry's Bats is it was hard to keep villains around because he was a lot more brutal then Bruce. Deliberately dousing Powers with his own nuero-toxin (Inadvertently creating Blight), knocking Bane 2.0 into his own Venom Patches, causing a (seemingly lethal) Overdose, and probably the most brutal bit...Throwing Ace down a laundry chute and following it up with a grenade before Terry knew Ace was a android.