Hi everyone, I'm considering buying my toons more merc slots from the Marketplace. FUNCTIONALLY speaking, is there any reason to have more than 4 total? Don't the J5 healer, tank, cast DPS, and melee DPS all function the similarly or do some of the legendary mercs have bonus abilities? Just trying to figure out if/why I would need more than 4 if I don't care about switching the skin as much as the role. Thank you again!