While i'd accept that if Diaby was fit more often he could have been a very useful DM/B2B for Arsenal & France - I'm not sure that potential best of Diaby would be better than Wilshere.
Secondly ha, I always find these "overrated English player" comments funny.
How can England, a country that has such a poor international record for a major nation, that the world mocks and its own fans have overrated players?
Who overrates them?. It sure can be the premier league or else the amount of ENG players in the league won't be under 40 %.
That logic doesn't make sense. Given ENGs history, ENG players are either not rated highly at all or in some cases, the actual good ones are under-rated because the general consensus the ENG system can't produce a player that the Spanish, Brazilians, Germans, Italians etc produce.
It generally takes a continental manager like a Wenger, Benetiz, Martinez, Houllier, Hiddink, Capello, Pochettenio to work with a few, hype a ENG player that is good before anyone seriously takes note.