Its not really an advantage that the attacker has but he can rotate his lineup in order to get the best outcome. For instance, the top person in my ranked battle runs a kurama, kisame, roshi, and fire main team. I run a skill broken konan to stop his kurama from resetting his mystery as well as stopping his Kisame from combo-ing to prevent the DOT damage from the ignite and poison. If I don't align my konan lineup with his kurama lineup, I always lose. It does take a little strategy despite what people believe. Some lineups fair better against others. Just make sure you're always rotating your lineups for the best outcome (if need be).