What really makes that work is the Man-Bat taxis... without them, the Batman enemies just take too long to get to where they need to go.

You might want to consider dropping Entangle or or Camoflauge and putting Sidekick on Clayface and one of the Man-Bats (the one that'll carry Joker). Since you are probably going to keep them all bunched together anyway to use the TA and share around Joker's sweet 11 AV, now one of your taxi/tie-ups also has Clayface's sweet 18 DV (20 in close). If I am adding right, you'd have to drop Infiltrate, too, to get under the feat cap, but I don't see you really using that feat, too much anyway...

300 points, Unrestricted:
SR Joker 97
V Clayface 89
+ Camouflage 8
+ Entangle 8
+ Takedown 6
+ Unstoppable 5
+ Infiltrate 2
Man-Bat Assassin 40
Man-Bat Assassin 40
295 points.

The keyword is of course 'Monster' - the fact that everyone has the Batman Enemy TA is just icing. Joker takes care of ranged combat, Clayface of close combat, and the Man-Bats are taxis and tie-ups.
A bit much with 29 points of feats on Clayface, perhaps, but I just couldn't resist it.

Let's do the timewarp again!
I'll definitely consider it, but I'm not sure I'd play them all bunched up together - I'd probably do a 'divide and conquer' play where Clayface wreaks havoc up close while Joker snipes from afar.
The reasoning behind Infiltrate is that it lets Clayface break away for free when using Charge on his top click by the way. It could easily be dropped, but the only other way to spend the points I could think of was to use Vault on Joker, and that seemed even less worthwhile.

Oh, I know why you'd want it, but it just seems to me that he just wouldn't use it too often. Clayface, to me, was always more of a Charge-in-and-pound-until-they're-KO'd kind of character, not really a hit and run.

If you don't want to use Sidekick, I'd definitely leave Infiltrate on there ('cause, yeah, Vault would be almost useless on Joker. About the only feat I would put on him is AP since he could really benefit from that his entire dial)... but I think you could get more use out of Sidekick.

Well, it's not really a question of hit and run... just the ability to choose your targets. Sometimes you'd rather attack from a different position - heck, it could just be that Clayface wants to move so Joker gets a clear shot to someone else. Not having to chance a breakaway roll can be kinda neat. Not to mention it can be used to pick up new objects as well.

But if I did have to choose between Entangle and Camouflage Entangle would definitely get the axe. Camouflage is usable up front, a huge plus in my book.