Socrates in the platonic dialogues

If Socrates is portrayed holding one view in one of Plato's dialogues and a different view in another, should we be puzzled? If (as I suggest) Plato's Socrates is neither the historical Socrates, nor a device for delivering Platonic doctrine, but a tool for the dialectical investigation of a philosophical problem, then we should expect a new Socrates, with relevant commitments, to be devised for each setting. Such a dialectical device – the tailor-made Socrates – fits with what we know of other contributions to the genre of the Sokratikos Logos, to which Plato was neither the first nor the only contributor.