In the corporate world, LB are fairly common, I'll grant you that. However, the NFL has only just permitted hedge funds to put money in. In 2005 it wasn't permitted for one simple reason: the owner wouldn't be the owner, but the lender would. Read up on this as there's still stuff around from 2005, though a lot has been scrubbed from the web. I have a Justia account so I'll check again on Monday as Westlaw and Lexis are minefields.
Lastly, it's incorrect to call the Glazer family the owners of Manchester United. They hold that title subject to their creditors who, believe me, wouldn't hesitate for a second to dismantle the club if the Glazers could no longer pay. It was this scenario that the NFL sought to prevent and did so. The British (like your own countrymen after 1945) sought (outwardly) to limit the Americanization of the local culture. But that's always been a facade for the British. We gladly allowed them in with our eyes blinded by dollar signs.