Ok before I sound like a complete a**hole. I should mention a compromise, say 50% ownership until "your" miner arrives. After that then you're 100% vested. So here are the scenarios:
- 1. Everyone's 100% vested from the begining
- 2. Once the nth miner is received only shared that helped buy all miner up to that one are 100% vested
- 3. Once the nth miner is received shared not represented by the remaining miners are only 50% vested
That might/will cause a new discussion when the units are not received in the order they were bought. You could say that the first miner received counts as the first one ordered, but one could also argue that, if the fifth one arrives first, that we wouldn't have anything yet without the investors in the fifth unit.