Sure there is. It's called pugging. If you're going to level a gladiator via group finder, you're going to need to overcompensate for players who either don't follow a kill order, assist the tank, or like to spam hard hitting aoes without watching their threat bar. Alternating targets with the ROH combo after only two flashes in content where you don't have access to shield oath is a dice roll. Flash spam is easier and more reliable.