I don't realy consider that applical in this case. There are a lot of good reasons to taylor a load to a specific gun , but in this case I see no practical benifit to apply. What is the payback vs having to manage a seperate loading and how important is it ? Not overall, but specificaly to this application.
Applicable. Tailor. Benefit. Specifically.
The two revolvers weigh in differently, potentially have different BC gap spreads, different cylinder lengths, different throat diameters, different forcing cone angles, different sight regulation (different range, load velocity, or bullet weight), etc etc.
SD isn't precision long range competition, but it's not an area where sub-optimal accuracy with either piece should be considered acceptable.
To the OP - I re-read your opener and your "idea" to use one powder, charge weight, primer, and case then identifying by the bullet would work, although there really isn't any reason to do so unless you're charging with a thrower, rather than weighing/dispensing your charges. I would encourage you, if you DO use the same powder charge weight, do NOT lend yourself to mixing up different powders. In example, a fast burning powder charge under a 180grn pill might be a mild load, and the same charge weight of a slower powder under a 260grn pill might be a hefty load, but the fast powder under the heavy pill might be a grenade. So if you're picking, say, 10grn as your charge, only use one powder for both (which I BELIEVE is your plan?).
You'll find the combinations will likely end up with a light end light bullet load and a moderate heavier bullet load, or a max heavy bullet load and a moderate light bullet load. You won't likely find one powder and one powder charge will drop both a heavy and a light bullet in the middle of the road. One will be on one edge or the other if one is in the middle.
You might struggle, however, to get both loads to shoot to your sights, that would be the biggest watch out even if it does work for you.