Carb = HP 2086, 70p single target, 70p AoE, 20% dmg reduction, 70p Stun
Titan = HP 2048, 85p single target, 70p AoE, 20% dmg reduction, 70p Stun

I don't see any difference but carb having little more HP while titan does little more dmg with ST move.

Can anyone please explain why I would play smn vs acn?

Thank you