Why do you focus on "25%" as what UM would be offered as a partial share? Simply to support your "B12 is better" agenda?
A 50% share for 3 years, with a performance clause, might be more realistic. If Miami starts in the B10 in 2026, a 50% share in the B10 will be approximately $40M, and by 2029 $50M. THEN you add the CFP payout to that figure. For a 3 year period. The B10 CFP payout is, I believe, double what the B12 is slated to be. That would put the UM media money well over the B12 number PLUS you are IN the B10, playing Michigan, USC, Ohio State, on national TV, building your brand, and attracting recruits ... rather than playing low tier schools, with 2 star players, on a streaming app.
It is unlikely that Miami, or possibly even FSU, begins play IN a new conference prior to 2026, regardless of when their departure plan is announced. IF Miami can make the CFP this year, and repeat as a 10+ winning program in 2025, that is more ammunition for maybe a 75% or full share. That is the way the negotiations should go at this time. Worse case 50%, based on performance over the next 2 seasons, 75% - Full share. The Big 12 is a death sentence for the program. The Big 12 WILL NOT be able to attract 4-5 star players even close to the current level, and it is WAY behind the SEC, B10, and current ACC (because of the players FSU, Clemson, and Miami have brought in).