Burnwinter I think what @daredevil is saying is (correct me if I'm putting words into your mouth) that there has been a considerable amount of criticism regarding our form this season, even though we've had to bed in 2 new players into a 3 man midfield - not an insignificant task - and we sit today top of the Premier League.
As for having to rebuild it all again in two or three years, surely for all the elite managers, rebuilding is a constant process (evolution not revolution) - Ferguson managed it constantly for the guts of 20 years and Wenger arguably between 97-04. Guardiola has done it at City, even if he may have gone a bit too far this summer.
In any case, I don't think you can guarantee anything in football - as I alluded to earlier, in 2004 would we have foreseen 20 years without a title after 3 in 6? Leave worrying about the far future to the people lucky enough to be able to try and influence it I reckon.