I don’t believe the Glazers can stay, but here’s my rough take on the numbers, mostly from memory and guesswork. Feel free to point out the many and obvious flaws.
Without considering the large premium Qatar or INEOS would likely pay, United are valued at approx 3.3B pounds, depending on what day’s stock price you take. The Glazers own approx 66%, say 2.1B pounds, giving each sibling 350M. For Avram and Joel to stay, they would need to pay the others 1.4B for their four shares, or around 700M from each of them. I don’t believe they have anything like that cash lying around, so that means borrowing, maybe from the Elliott vultures. 700M for a 10 year term at 6% gives annual repayments of around 92M, which is far beyond what they can take from United and hopefully far more than they can afford.
If the Glazer siblings want full Qatari value for their shares it makes the repayment figures above nearly 150M per year.
I don’t see how they can stay, but I am nervous that Elliott could structure a deal that makes it possible, while increasing the likelihood that the Glazers default (or maybe die) before the repayments are complete and hand the club to the vultures.