Man you are really doing serious project.... I don’t know much but I think you need to go for un-welded vertices … also I think some real physics should be used like pressure, also the vertices in all skin model should be relative (e.g. pushing one vertex forward should cause a shifting effect with different distances to the surrounded vertices) and when you remove triangles (for wounds) you need to show skin depth for realistic simulation.
All the best
All the best