Am currently leveling up a pve group (~35 atm) that will eventually consist of 1 prot Paladin and 2 elem Shamans for the purpose of pve - namely heroic instances...

So, the question I wanted some opinions on before I get there and find out, is do you think 3 maning instances will be possible? or will there not be enough dps/heals to survive? essentially, Should I stick to 3 accounts, or go all the way and get 2 more if my aim is for some instance fun?