The issue is when a flanker is specifically targeting Zen on his way from spawn. And I strongly disagree with you. Zen provides sustain, debuff, and a crazy amount of DPS against the right targets. With a Lucio, a 2/2/2 comp is potentially running a team with 6 competent damage dealers. That's not something Mercy or (console) Ana can provide. It is absolutely crucial Zen stay alive as long as possible, and if that means peeling another player to kill a harassing Tracer, then so be it. And obviously, if one healer is Lucio, the other can't be. That leaves Ana, Zen and Mercy. Ana on console is just as vulnerable to flankers as Zen, probably even more so cause she can't land headshots. And I hate playing Mercy.