It is crucial that standards of whether vocabulary helps us cope with the world better than another is internal to a given vocabulary. The external reading (which sometimes one gets the impression that Rorty is using) is that coping talk comes from a biologically reductionist notion of “what is good in the way of belief”, e.g. the mention of Darwin. But the invokation of Davidson in the above quote is important: his interpretivism is that the content of your beliefs are what my (as a fellow user of a similar vocabulary) best interpretation of what your behavior is. This is inherently internal to our language practice, not something that can be directly held up against biological selection pressures.
We can invoke representations as part of a causal explanation of how a certain coping strategy works, and why it is as effective as it is (and no more).
For Rorty, coping, conversation, and redescription are three ways of talking about the same thing. Coping is deploying reason-relations in a practice of giving and assessing reasons.