To be fair the only way to succeed these days is with a chequebook. Now, I personally don't like that, but Gerrard being a "chequebook manager" means he's an ideal fit because the only teams winning the league are those with massive bank accounts.
Does Guardiola improve players? Not directly, no. I mean if you stick 30-40 world class players in training sessions together then they will improve, but that's not Guardiola doing anything special, that's just a side effect of spending £1 billion on players.
I think people look at Leicester winning the league and believe that is still possible, but it's not. That was a fluke, a one off, and Leicester will never win the league again unless they break out the chequebook. If you want Villa to be the team that improves players, then you're also wanting a Villa team that will never win anything again because that model is dead.
Man City, Liverpool, Chelsea and Spurs are not improving players, they are buying world class players and doing the bare minimum to keep them world class.