Remember my post when I said the unbeatable trio illustrated below "might be beaten by the water summoner"?
Well, I was dead wrong, the water combination was beaten by the TRIO. Please see the pix below;
The Result
Indeed the Trio is still the best combination in the 18 mana cap. However, a fellow player commented that it can be beaten by snipers, I doubt if it is possible because snipers will keep aiming at the shieldbearer and the healers will keep healing. But I'll keep you posted if something like that is in play.