Maybe it's not about winning
I don't know about others, I do enjoy a good race, but I abhorr car damage... Especially for vintage car classes.
For me, enjoying racing with mates is my fun. A win for me is ending the day without a damaged car. I would hazard to say that the appropriate motor and fdr, would be the one that allows the car to get around the track without damage and is easy to drive (again, lowering damage potential). This is track specific, so a larger track with bigger jumps would require a fdr and motor to be hotter, to ensure car longevity. And a cooler motor for flatter, twister tracks.
if parity is a concern, then race organisers can control both motor wind and fdr.... after first testing the track.
For me, I hate tracks with too many jumps... cos its hard to race on. Cars cannot race in the air... whilst I enjoy big air too, a track with too many jumps just doesn't make for good racing... too much luck involved.