Small caliber bullets can and have killed all sizes of game animals, IF the conditions are right, which is also true of large caliber bullets. BUT, if the conditions are not just right, you have a better chance of recovering an animal hit with a larger, more powerful bullet than a poorly placed small caliber bullet.
In theory, sure, but I can’t prove it from experience.
The things I’ve hit poorly or seen others hit poorly, then get recovered (which is the only way I can say with any certainty where they were hit), whether they were shot again or not……show zero correlation between cartridge (or even velocity) and recovery.
My sample size over a lifetime is only about seven deer that were hit marginally then recovered. Three with follow-up shots later, four without. That doesn’t count deer that were hit repeatedly before attempting recovery - if it’s still standing I’m still shooting, even if it’s dead on its feet. The only exception I’ve ever made was a very obviously lung-shot deer. It stood wobbling for maybe 20 seconds, I should have shot again but didn’t. Felt bad about it later.
Again, my sample size here is only seven(?) that I remember, but one was with 6.8spc, ran 60 and died, one with smokeless muzzleloader with a very light load, ran 20-30 and died, one with a very powerful load from smokeless muzzleloader, ran 50-60 and died, two with 7mm-08, one ran maybe 200 and died, one ran maybe 150 and was shot again. Two hit poorly with .300wby. Both took follow-ups from a 6.8spc.
I watched four of those get shot and helped recover the other three. Fired the follow up on two of them.
The only thing I’ll add here is that none of those 7 were initially hit with ‘match’ bullets. From what very little I’ve seen but many volumes of documented kills I’ve read about, deer hit with ‘splody bullets, regardless of size, even with marginal hits, seem to be more likely to stop and offer a follow up, whereas deer hit with more heavily constructed and/or slower bullets, seem more likely to run.
*shrug*.