Because Mozart was developing the form of his concertos as he wrote them and not following any preconceived "rules" (apart, presumably, from his own judgement of taste), many of the concertos contravene one or other of the generalisations given above.
Debido a que Mozart estaba desenvolvendo a forma dos seus concertos mentres os escribía, sen seguir ningunha "regra" preconcibida (a parte, presumiblemente, do seu propio xuízo de gusto), moitos dos concertos contraveñen unha ou outra das anteditas xeneralizacións.