Hmm, this is a new idea. You'd think with their super powers, the Loonatics would have an unfair advantage against many of these powerless villains, but if WB DC cartoons have taught us anything, it's not to underestimate unpowered heroes and villains! Plus most of these Gotham rogues probably are more seasoned in what they do than the Loonatics who are relatively new to superheroing.
I think i agree with Akira that i'd see an all the Loonatics face all the Gotham villains. Why settle for just two combatants?