Why? There's a load of SD fighters with giant bobble heads & tiny limbs, and they don't suck.

Gotta keep in mind that the images are only mockups, it's rare things don't get changed several times through dev from the initial concept & if the limbs need reworking then they'd end up reworked.

It's more about the idea at the moment than being picky about the little things - those are for later on down the line.