If some members are contributing much more (in terms of effort, time, cash) then dividing by 6 equally will also mess with morale and effort. This touches in to pg's point about cliffs (which I understand means when you leave, your equity leaves too) and jasonlbaptiste's point about clear roles and responsibilities.
If responsibilities are equal, so too should equity. It's possible to not define equity at this stage so that it can be fairly allocated at a future point based on actual contribution, but that can be messy and time-consuming, which again takes away from speed.
any sort of unequal distribution will mess with moral and effort