How to make better Roblox characters

Personally, I dislike the current Roblox avatars, every time I see an animation where my entire arm comes flying off to go do something, I cringe. Roblox’s characters are known to be very “LEGO-y” and I now want to move away from these default characters and animations.

I have been learning Blender, so I do possess the skills to create better avatars, but after learning Blender I learned quickly that a single mesh cannot have more than 10,000 triangles, which would mean I could maybe make an arm.

So, I could try to make each limb a different mesh and put it all together, but this could lead to issues like the meshes not moving together or the animations not being in sync, so if anyone knows a way, or any better way, of achieving this, I open to suggestions.