What exactly is the difference between a reel designed for one line wt. and another line wt (lets assume were talking about the same model). For some background. I have a 3wt. TFO and have been looking at ross rhythm reels. Are the line wt.'s for a given reel determined by the weight of the reel which I can assume would be better fit for balancing a fly rod of that same weight? Or is there something else that plays a part in what designates a reel for a 3wt line? Would it be better to go lighter and (if I ever needed to) use the lighter reel with a heavier line than to do the opposite?.