With regards to the Etihad sponsorship being "friendly", I'm sure that quite early in this thread @Prestwich_Blue has said that in one particular year (think it was the termination of Mancini's contract) that City asked for some of the following year's money
It all worked out as the agreed amount over the period of the sponsorship, but City received something like £80m one season and a reduced amount the next
Having a friendly deals with sponsors is not a crime anyway.
I remember talk years ago about adidas or Nike (can’t remember who at the time) helping United fund buying Ronaldo back.
Based on it being a win/win, Etihad having a 10 year sponsor deal to get maximum value front loading made sense.
As did a drip fund so to speak