Whilst being key players in our team isn't exclusive,the points I made about each individual's position at the time should back up why they were still elite calibre then as they are now.
It's not a fact, and it's blatantly incorrect that a player with 91 International caps (c55 of which were obtained prior to joining City) was "on the fringes" of the Spain squad, had question marks over his ability and that Toure was an over priced Barca cast off.
This reminds me of the guy on talksport who'd never heard of either of them and quite rightly had a City fan make him look more than a little ignorant.
I think the crux is, I disagree with your last paragraph - although I'd absolutely concede that the standard of footballers in certain positions seems to be lacking: mainly defenders. I don't believe we're suddenly only going after a calibre of player above 2010 Silva/Yaya.
a. Because I'm not sure there's a level above them other than the Messi/Ronaldo bracket and
b. Because we're still signing Fernando's/Delph's/Sagna's - which means we're not exclusively chasing that top tier player and therefore our pool of players shouldn't be so small and thus our transfers be so difficult.
I think we can only buy what's on the market, and two of the best attainable midfielders (Pogba and KdB) we've attempted to sign. To me that says we aren't settling for what we have, but we needed homegrown, and we needed some sort of fallback for midfield anyway, and that's where Delph fits in. Great buy for the price. I think if we COULD buy a right back better or as good as Zab, we would do (he's not getting any younger), and right back is in even more dire need of improvement.
We can't have complete team of superstars and no water carriers, I accept that, but I'm pretty sure some of the 'lesser' buys are well reasoned plan B type players rather than plan A buys. I can't believe for a moment that Delph was the first name on Txiki or Peller's list, but I can believe he was an opportunistic buy that offered a lot of pros, and very few cons, so was an no brainer for us.
I disagree about the perceived calibre of a player all those years ago reflects on their status in the team today. In the case of Yaya and Silva, yes, they've been brilliant buys, and remain critical to us. But at the same time, Zab and Vinny were cheap buys who have also been (and remain) critical so us. All the while, there's been countless other big name and expensive signings who've been and gone, so it's a self fulfilling argument to put forwards the obvious successes as proof.
As for Silva and Spain, he wasn't generally a Spain benchwarmer, and not a regular starter - David Villa was ahead of him (a player we were linked with at the time too). His stature in the Spanish squad has increased considerably SINCE joining us. I say 'on the fringes' because that's how we was commonly described at the time. He'd playing about 40 times for time, but in a lot of friendlies and as a sub. I also didn't say there were question marks over his ability (per se), I said there were plenty of questions marks about his physical stature and ability to cope in the PL (physically). That was still the case after his first season, albeit less so, but questions still asked.