I feel that Olaf and Jayce are strong picks for that 3v3 map.
also, I had a plan - Ashe+Twisted Fate+Olaf - we've won against Fizz+Darius+Rengar.
why ashe tf?
well, those altars give more gold per minion (+4). TF passive gives gold per minion (+2). now look at Ashe's skill - it gives gold per minion too! (Bonus Gold: 1 / 2 / 3 / 4 / 5)
so, to count it up - if You go into a troll mode and max Hawkshot first, you get +11 gold per minion if you have got at least 1 altar. imho that's alot, especially if you also get 1 gp5 item just to troll more.
rengar can rape ashe, so does darius. yes I know, but when I started to actually do epic Man Mode Olaf teamfights after ashe+tf stun that was not a problem.