75% of 120 million is 90 million.
Accounting 101:
Total Revenues for MASN: $150 million
Less Costs:
$60 million to the Nats for broadcast rights (It'll be less than that for 2022-2026)
$60 million to the Os for broadcast rights
Other costs of operations ???
Profit - something less than $30 million ($150MM - $60MM - $60MM - ???)
Profit is what gets split 75/25. It might not even be a profit
The sweet part of the deal for the Os is getting the same rights fee as the Nats under the current arrangement. 75% of MASN's profits isn't that much. If I were Rubinstein, I might say "Fine, Ted, you guarantee the Os the same rights fee as the Nats, which we base on some formula (a bundle of comparable teams), and you can fold MASN into your network."