The highest is actually 18.6m a year 😃
But I think Madison Square Garden and Barcelona are a tad more high profile than COMS and City. It's a bit like saying if a Bugatti Veyron can go for 2m who's to say a Ford Focus doesn't deserve the same. It also opens a ridiculous can of worms if it's allowed as they could pretty much sponser anything and everything to get by the FFP rules.
It's hard to get into it without a breakdown, but it's got nothing to do with what they deserve and everything to do with what you'd expect a club in their position to get. With Tottenham and more importantly Chelsea struggling to get even £10m a year deals, you can't say it's at market value.