Creating customisable characters

I understand that that is A way of doing it but is it the best practice? i mean;

where as here he basically covers up the arm/leg mesh with the glove/boot. would it not be better/more optimized to have the leg as a separate entity that is completely replaced when the new piece is equipped? so as not to waste the calculations on something that the player is never going to see.

Sorry if I’m not explaining myself very well.