i would say with that makeup if you guys didnt play like retards and be patient around the 10-15 min mark yall should be able to trade with them and even engage on them and win.
i actually have my better games when im on melee heavy teams, but then again im usually playing with 2-3 friends so coordinating engages and fights works fairly well. id even wager that some of my best games have been playing champs like trundle, zac, wukong, xin zhao, volibear. just my .02