Lol, to what end? What is this collateral meant to insure? See red font above, you're not making any sense.
To make sure cowboyminer will host the needed hash-power.
If cowboyminer would break his promise to host before receiving 35 miners from you, what would make him keep it after getting 35 miners? He gets his collateral back, gets 35 miners that are worth something and ...what am I missing?
Curiouser and curiouser.