I've been thinking more about this (whether Veritaseum could technically perform the same function as Populous).

Veritaseum can tokenize all sorts of different assets.  I can't see any reason why Veritaseum couldn't be used to tokenize invoices.  If Reggie wanted to do this, I don't see any reason why he couldn't.

Remember, Reggie Middleton is a badass.  He's the Elon Musk of the FinTech world.  Just like Elon might wake up one morning and decide to dig holes under Los Angeles and the next day you'll see huge boring machines outside his building.  If Reggie decides he wants to eat Populous' lunch, I'm pretty sure he'll just do it.