I think what's often missing from these hypothetical discussions about ADUG takeover is that Mansour didn't necessarily buy City off Shinawatra in the traditional fashion. It was a last-minute purchase, proper minutes to midnight stuff, cos his assets were frozen. We were on the brink of going into administration.
Having Garry Cook on the board would have probably seen us bought out by some Americans instead - plus he had some great ideas that would have kept us moving forwards anyway - but the period between 2008 and 2010 would have been tough. If we'd managed to avoid near-instant relegation after going into administration, we would have probably become a good mid-table side, finishing between 6th-12th, occasionally going far in the cups.
But we've seen with teams like Leicester, Southampton, Swansea, Bournemouth, West Brom, Burnley, Villa etc. (even Everton) in recent years that a couple of bad seasons can suddenly get you relegated (or nearly relegated) and all the hard work ends up being for not much. Loads of teams have had to start all over again after failing to keep hold of their players.