This is one of those posts that illustrate the difficulty of constructing a valid answer. Not enough facts provided and then there is the issue of what the golfer feels versus what is actually happening. Video would be a big help.
Then Kevin and the other instructors could offer specific advise.
My thought about wider stance was made from personal experience. My tendency is to get lazy, and end up swinging, let's say Driver, with a too narrow stance. To me any tip like, try wider, or try more narrow, should be
taken as try it incrementally, a little at a time.