only muslim men

Better hope they don't find our about each other or a cat fight will break out.

is this man rich? if not i doubt it he could afford it

Logistically infeasible. Eventually cross schedule conflicts would occur, and even if in different towns, locality becomes a barrier. Can't 100% compartmentalize or control the flow of information. You'd have to be either very invested in a nonsensical pursuit, or most of them would have to know they were in a polygamous scenario... I think if you did a "polyamory" thing it doesn't count as a girlfriend either. I was just thinking of someone I know who found out his father was a bigamist after he died.

Maybe a cultist could manage it

but the real question is why would you want that ?