Very interesting observation. Yes. That would be a valid comparison. There were 29 "types" of gladiators that were almost depicted as "characters". But keep in mind that they weren't always made to fight other types. For example the Equites were mounted gladiators and only fought other Equites. Wheras the Hoplomachus (designed after a Greek hoplite) normally fought a Murmillo (styled after Roman legions from Gaul) but sometimes teamed up with a Thraex (dressed as a Thracian soldier) against a Murmillo dressed as a Roman legionnaire. What I'm trying to get across here is that these "characters" were not just for fun, they represented groups of people, and sometimes characters in a story, or in history. They would recreate battles with certain gladiators pitted against their enemies representing real-life enemies. So some of the pairings were logical.

From what I can find, there's no particular type that fought other types that was particuarly overpowered (ie: mounted gladiator would be seen as overpowered, but only fought its own class) but the three previously mentioned plus others similar armour were the most popular - and usually fought each other with none of them being vastly stronger than the others. These popular classes had fandoms with names (no shit). The Secutors (equipped with an oblong or "large" shield called a scutum), whose supporters were secutarii.