Why don't you help him set up then and get a cut 10% out of all work going forward, 10% over a few years will add up towards a little retirement fund.
He can work as a sole trader, and when you get these 750 houses, that will be a lot of 10% in your pocket.
I employ lads, and over the years they come and go, I have 1 lad who I have helped set up himself, he does part time for me now and does 3 days a week for himself. I don't take nothing off him, I just like the guy, similar situation he's got a few little ones, so he can earn a bit extra.
It doesn't clash with my work so there's no issues
Matt