The problem with a Rex at 243 speed for me is he will use his second special since there are no debuffs present. Now he has wasted his turn and I can smash. Also, if my Sass has 2 buffs (TWO BUFFS) from shroud, when she electrocutes Rex he is GUARENTEED below half health. Then my savage smashes him with full protection and bye bye Rex. Honestly, most Rex's I face on offense never get to take a turn.
My team start is obv for offense. There is no point in trying to theorize about defense anymore. Everyone easily beats everyone now.