The distinction I would make is this;
If you are offering 'the world' your own philosophy, and proclaim it as such, then it is quite likely to contain elements of past philosophy, including Nietzsche's.

This Nietzsche did himself with Schopenhauer; he learnt from the latter before creating his own philosophy which of course had Schopenhauerian elements within it.
However, by this very act of creation, he DID 'reject' Schopenhauer.

In fact this process is somewhat Oedipal.

Now there is the other type, who claim to be representing what a particular philosopher said, and tell us that they are true to that philosopher's vision.

Such acolytes have no business in saying that a part of such a coherent, organic philsophy as they espouse, is a "mistake"!
This is IN ITSELF A REJECTION OF THAT PHILOSOPHY!

The only difference between such apostates and real philosophers is that these acolytes have not the wit, wisdom, or honesty, to create their own philosophy.

So I say in fine, that an expositon of a philosophy - such as I attempt here - should be warts and all; it cannot talk of "mistakes" on such fundamental matters as (in Nietzsche), Order of Rank, Politics, the Jews, Antifeminism etc.,

However, an Antinietzschean philosophy which may COME OUT of Nietzsche should call itself such, AND NOT PRETEND TO BE AN EXPOSITION.