What's your faith? I would prefer gladiator because of the stun for 2 turns in a row the damage lose dragoon but 2 turns stun is pretty big deal in arena and pve imo.
Vincent Gladiator is better for PVP due to the stun effect of his skill. Vincent Dragoon is a little subpar with Gladiator but can still be useful when dealing with ranged units at the back line with his Leap skill(and he's quite useful in clearing the gold mine event dungeon too)