Well, on a lark, I cloned an Eevee egg just a few steps short of hatching in order to test out whether Exp. Share imparts an equal amount of stat experience as well as regular experience.
I gave one Eevee a Pink Bow and the other Exp. Share in order to test this. I noted that both Eevees had identical stats, and I'd watch for any deviations from the two.
Well, after wading through Furrets, Pidgeys, and other critters around New Bark Town, both Eevees have identical stats at level 10. Interestingly enough, both Eevees had the same Happiness level, even though only one did any actual combat. This verifies the fact that, while it's nice to make your critter fight to raise its Happiness level, it's not necessary.
Unfortunately, I don't have any recorded results from this. I decided to let one Eevee evolve into Umbreon ASAP and wait on the other Eevee to let it evolve into Espeon. However, I suspect that the results would be the same for any Pokemon under these conditions. Yes, one twin *can* do all the fighting while the other loafs off, and they'll both have *exactly* the same stats.
Any questions, comments, or criticisms are welcome.
To claim mastery is to imply that there is nothing else to learn. Thus, I shall never be a Pokemon Master, since there's *always* something to learn.