[...]
I am entrusting the miners that need to collaborate and play fairly to profit.
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otherwise you are "relying on the good will" of humans again.
Seems like a contradiction, could somebody please clarify?
There is no good will or bad will, just economic will in PoW. If you do the right thing to obtain maximum profit possible from mining, you are actually obeying and enforcing the protocol rules. It's that simple. Do the wrong thing and you lose.