Assuming you guys are throwing Rock types, 4 should be decent at handling Moltres even without full optimized stuff. It's weaker than a normal T5 is for the special appearance, and it has a lot of common weaknesses, one a double weakness, to types that often see Weather Boosts. I've done a 4 man Mewtwo with a bunch of ~35 players throwing glass cannons like Gengars or random Crunch Ttars, so Moltres, who's all around weaker and has more type advantages to exploit should be fairly simple to build for.