when i use the same shoes and cleats on several of my bikes that are fitted with compatible pedals and otherwise set up the same, which my bikes are, i always assumed that anything that felt different, whether right or wrong, was attributable to the differences between the bike's frames or wheels or tires or the materials they are made of. i don't think i am alone here.

the only bike that i regularly ride that could exhibit a noticeable q factor discrepancy would be my MTB with a triple. and if it did i would ignore it rather than attempting to widen all my other bikes in order to create uniformity. but if you actually have a manual that addresses legitimate pedal shimming tolerances and you only have to fuss with one, i say go for it.

OTOH, i think i might first try deciding which one i liked riding most. if only to avoid the possibility of owning two bikes with a uniform but sub-optimal q factor.