I have a little idea, but many players would have the same skin and I do not know that many Minecraft players who would do that. So you could with a texture pack, e.g. The skins of all players change (only I can see that)? For example: All the players I encounter on Gomme have a Steveskin, Snowmanskin,? Would I be happy if someone knew that.
Of course this is possible, but only for the players who have not uploaded a skin. Because then this skin is always downloaded.
But for players who have no skin and only use the standard Steve or Alex Skin you can change the textures in the resource pack:
Thanks, I also guessed. But wanted all the players I see have the skin.
Would be possible on a cracked server, since the skins are not downloaded here…