I think that was partly his point. I'm not convinced Pep is some amazing manager but I do think more players have improved under him than got worse and given that they try and buy the best players and often at young ages then you'd expect that (as you suggest). Some are arguing Sterling isn't better than he was, I'd say he is and that it's normal. Pep factor? Could he hack it at Burnley? I'm not convinced but who cares, he doesn't and neither do Man City fans.
If people want to argue he's a fraud though then his trophy record, accompanied by all those managers who have failed would suggest otherwise. Can you compare him with managerial greats like Clough, Shankley and Ferguson. I'm not convinced you can given what he has at his disposal but City are simply the most recent in a long line of teams accused with "buying the title" and they won't be the last.
Clough turned an unfancied Derby side into Champions and then took Forest from the old second Division to league champions and then European Cup winners ... twice.
Best manager in my life time for me cos he had to build both teams with out the pull that United and Liverpool.
Think it is impossible to quantify how good PG is.
His style of football is great but
1. He inherited the best Spanish players in over 40 years at Barcelona and left when their team needed rebuilding so never did that.
2. He was at the best and richest club in Germany.
3. He inherited Kompany, Stirling, Aguero, Silva, Toure, De Bruyne and Gundogan...he then spent £209m in his first season to come 4th.
Lampard has been sacked for for not challenging for the league after spending less than that with a worse team.
4. The following season he spent another £180m to win the title and the league Cup.
5. Then the following season he spent a further £71m and won the treble.
6. Then last season he spent another £75m to win the league Cup.
7. This season he spent £123m and will win the league, probably the league Cup and is still in the FA Cup and CL.
It is a brilliant amount of trophies in 5 years but after inheriting those world class players and spend £660m (2/3 of £billion) in just 4 and 1/2 years you could argue that 3 titles, 3 league cups and an FA Cup is the minimum he should have won.
8. He has not won the CL league since he did it at Barcelona. Since he got to City he has not made it past the 1/4 finals which is a very poor return.
9. For someone who is rated as "improving players" he has been pretty hit and miss with his transfers.