I would advise against mixing matching methods since in that case you don't really have any sort of consistent scaling between fovs. Converting from your base game to the converted games hipfire is pretty much the only scenario were you might want to try a different method, 360/cm should even work pretty well, especially if you're converting to a TPP game since the" correct" conversion often ends up feeling too slow. However from hipfire to all the other aims in the converted game I'd stick to using only one method so you get consistent scaling. It is worth noting though that if low fovs feel too slow on 0% using a faster hipfire is only going to make the difference bigger and as such exaggerate the "issue".
Have you tried using vertical 100%/horizontal 56.25% for everything?