Why did Vince book Scott Steiner as a face against HHH? It made zero sense.

The short answer is that HHH got that opportunity just like he got many opportunities in the company because he wws plowing the CEO's daughter.

Vince single handedly ruined Steiner's brief run in WWE by booking him as a face. Big Poppa Pump as a face was never ginna work, he was a guy who always had to be a heel. Yeah his foot was messed up when he signed on and he tried to hide it until he had his money locked in, but he still performed well enough to work around it until it healed better.