Only Chainrai is noted as a secured creditor (although I expect HMRC to challenge that in some way).
If the footall authorities withold the parachute payments to pay the football debts, it may open up legal challenges, if not then HMRC share as you say will rise.
At the end of the day, football debt will be repaid in full and PP will be used to pay the debt, it's only a question of how.
I also doubt the PL & FL will have time to ratify or agree to the new PPs schedule for those relegated this season.