Can literary texts be redacted with the help of other texts incongruent to them?

Under what conditions and how is it possible to redact literary texts with the help of other texts? If there is only a limited degree of intertextual relation between two texts, can we utilize part of one in redacting a section of another? While there are many other differences between texts semantically and in terms of key words and in their totality, are we still justified to employ one or two aspects of a text in editing another, disregarding all other aspects? Is it permissible to make use of only the outward appearance of words and idiomatic expressions in the emendation of some other text?