Look. It may be superstition, but it seems that strings are important to the pros who are trying to make a living playing tennis. At the top level, most pros find a string combination that works for them and often stay with that combination for years. Then they switch racquets during a match at specific times to make sure they have the right tension.
Yes, a good player can play with just about any set of strings, just as a good player can play well with just about any racquet. They will generally play their best tennis with one racquet and one type of string(s).