I have to admit though that I have grown more sceptical about the relevance of the exact details of the team rating formulas for the game engine.
The BBs have said that the sector ratings have no relevance to the game engine themselves. They're there to give us an idea of the relative strengths and weaknesses of the teams.
The only thing I can recall the BB team saying on this issue is that comparing team ratings is not a good tool for explaining which team won, and that PP100 is a better indicator of that.
My understanding is that team ratings are an input in the game engine in some form, together with individual player skills.
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."