All the many ...isms

There's empiricism, reductionism, rationalism, historicism... the list goes on.

Some thinkers are portrayed as either or, those who follow the ideas of one are often in a perpetual quarrel with those who follow the ideas of another.

But is it really that black and white?
For instance, I have a hard time seeing how a reductionist approach to a problem can be only that, and not contain some aspects of holism, which is often regarded as that particular ism's counterpart.

I think that relativism cannot function without some ideas that are considered fixed, almost like temporary axioms. Not quite absolutes, but still not considered relative to whatever the relativistic approach seeks to shed light on, if not for any other means that communicating it. In another context those "temporary axioms" may be invalid, as the core belief is that everything is relative.
Similarly, how can absolutism function without at least some dynamic relation between the perceived components of a given subject?

I get the impression that some view themselves as reductionist, some as rationalists and so on. But wouldn't it be more beneficial to the progress of one's work if one were able to incorporate all these methods of thinking rather than just favor one?