First of all, you've completely missed the point. Regardless of how better or worse the two squads were when both managers arrived, I was responding to your argument that City have paid more on their defenders than Utd have and that being a defence of your poor defence. This argument is a nonsense. Utd chose those CB's and you can be 100% certain that when they drew up their list of targets, the fact that you were signing Pogba and Lukaku for £90m apiece was factored into who you could therefore go after. Utd and Mourinho have chose to concentrate their funds on other positions and when you choose to spend 2x as much on your central midfielder and striker than what rival clubs are spending, you cannot then complain that your rivals have spent more on CB's. Again, had Utd chose to only spend £50m each on central midfielders or strikers then you could have afford to sign 2 x £70m CB's - Utd/Mourinho chose not to though.
Of course you can complain. When you have Aguero, KdB and Silva you don't need to splash out on attackers or midfielders as much. Splashing loads of money on defenders when you have a weak attack and midfield would have gone down like a lead balloon. I really struggle to see how you can suggest that United and City were in a similar position squad wise when Pep and Mourinho took over.
As for your post, I've been over this before. Utd and City finished on level points and lets not try to rewrite history regarding the perceived quality of the players you've listed. Prior to Pep/Mourinho arriving not a single Utd supporter is swapping Rashford for Sterling (the latter was verging on a flop in his first season at City), not a single Utd supporter is swapping Martial for KDB (remember KDB was playing as a wide attacker pre-Pep), Otamendi looked like a car crash defender (I'm not sure he's much better now, he just has less defending to do), Fernandinho was decent but nothing more, Kompany was and still is nothing more than a squad player due to his injuries, Silva imo looked on his way out (there was lots of speculation that he would be sold by Pep when he arrived) and like KDB was very much a front 3/4 player rather than the central midfielder he is today. The only player from City that you've listed that is still performing the same role and at the same level today as they were before Pep arrived is Aguero and you could probably argue that he's not as pivotal to City now as he was then. The City side that Pep took over, or at least the side that last competed for the league was based around Hart, Zabaleta, Clichy/Kolarov, Toure, Silva (in an attacking midfield role) and Aguero - only Aguero remains.
Thats complete rubbish. KdB was an amazing player before Pep showed up and I would happily have swapped Martial for him. Rashford had potential and I'm sure a lot of us would have kept him over Sterling but there wouldn't have been much in it. Fernandinho was a fixture of the City team if an unspectacular player and Kompany was always quality when fit and a large part of their team leadership regardless. Otamendi was a quality defender before he came to City and despite his poor start there was always a good defender there. Saying Silva was finished is also a bit of a joke. He was always a top player and a massive part of their squad unless injured.
I assume that based on your equation of PL points total equalling the quality of a squad that Chelsea had a rubbish squad the season Mourinho was sacked? City have had a better squad than United for at least 8 years now and the distance has just grown recently.
Yes City have spent £100m odd more than Utd in the past three summers since the two managers arrived (although most if not all of that is covered by Utd paying more in wages) but that only makes up part of the difference between where the two sides are now. Pep's improved players and in some cases transformed them into completely new players, playing new positions but he's also spent better. I said at the start of this thread, Utd have spent poorly - far too many players have flopped and even those that haven't, there's very few that you could argue have performed over and above what you'd expect for the fees you've paid. Lukaku and Matic haven't been flops but equally they've not been massive successes either. City (under Pep at least) have bought in players to fit a particular system and way of playing and these players have been pivotal to allowing City to play this way and produce the best PL season we may ever see. Utd on the other hand have had this scatter gun approach and 5 transfer windows later look no closer to competing for the title than wen Mourinho arrived.
I'm not questioning that Pep has been great for City but everyone looks better when they are in a team that is happy, playing good football and winning. Mistakes don't matter so much, players can take risks and no one is complaining after the game if it cost a goal in a 4 - 1 win. We have spent poorly but I have no idea how anyone in their right mind can think that United:
A) Started at the same point squad quality wise when Mourinho/Pep took over.
B) Don't have budget constraints unlike City
C) Can magically ignore 3 previous seasons of utter mess before Mourinho took over.
Whats the saying "buy cheap, buy twice". Mourinho has clearly been after new defenders and the club has penny pinched on them. Either Mourinho says "no, I don't want them" and he gets nothing or he hopes they come good and he has bought a gem. I wonder how City would be getting on if they hadn't bought an entire new backline and keeper in the past 2 years?