Gladius=sword
Arcus=bow
Pugus=fist
Lance

The translation team did a great job here.

Now, the actual classes themselves can be made more distinct quite easily. Pugilist is a Gambler, and his abilities could be made to represent this (although now they most likely make it branch into THF + MNK). Gladiators are pretty traditional Greek Gladiators with the colosseums and whatnot. The abilities can be remade into "Zeus' Wrath", "Poseidon's Fury" and whatever. Marauders are like pirates. Again, very easy to build the class based on that theme.

But... OMG FF FEELING