Different training plan, some weeks injury, a bit weaker talent and subs make also a lot of difference once players get older and reach higher levels on the long run. Also a big difference on the long run if one or to matches are played.
Then there is the mathematic, for instance managers who go the "pace first" way will always win on the long run since this skill loses more effective training value per saison than the others do.
hi guys! there will be a lot of tec training in my team next season (>10) so with a bit of luck he'll reach the triple superdivine on the left side. alas, only a little chance for superdivine mid but I don't complain (not my merits so far, just bought him 8-]