Being a retired IRS agent, I'd like to chime in with some info I know. In the early 1960s, there was a tax case litigated involving 3 railroads. My memory may not be accurate, but I believe the parties were the PRR, the NYC, and the P&LE, and the issue was whether or not two unrelated parties (PRR and NYC), each with 50% control, could control the pricing of transactions with the commonly owned party (P&LE).
If my memory is correct, you know the P&LE owners, by law. And, by the way, the tax issue was resolved in favor of the government by finding that PRR and NYC acted in concert to control the tax outcomes of transactions involving all the parties.