Any kind of psychological injury should be resolvable by either approach. Sync and mastery would also be able to alter the perception of the stimulus as that is all created in the brain. In terms of actual physical injury I can see either being used to trigger the placebo effect, encourage people into a comatose state, and indirectly affect the body by calming emotions, easing sleep, etc but suspect that detailed mind-over-body stuff would be beyond the knowledge of the era - in practice phsyical healing is so straight forward with negation that the much slower method of finessing the brain to manipulate hormone releases, etc to encourage the body to repair itself at a faster than normal pace or in directed ways, which are in theory quite possible with either mastery or sync, wouldn't have been discovered.