A More Simpler way to apply Mannequin Skins

Mojang just implemented the new "Mannequins" a new way to make NPCs in Minecraft, now replicating the look of players. With this in mind, you just put the username of the player to add their skin to the mannequin, but what if i'd like another skin? Resource Packs of course, but, not all of the time i'd be dependant of resource packs, sometimes i just want certain skin to add but the player profile is not using it. How can mojang fix this? Using an "Skin ID" system, each skin has a dedicated id to it, now, when using commands to spawn a mannequin, you can use three ways, Player Profile, Local Storing (Resource Pack) and Mojang Servers (Skin ID System). This can be a more efficient way to extend the possibilities with this new mob, and a lot more.