>>534112205
Sure his expertise is mechanical, but this time he's working with Gero and Towa, so it's not a stretch he would, with their help, create something biological to put his brain in.

>>534112708
>>534113017
>>534113285
The movie doesn't show it, but in the Japanese dub they have a stoic tone of voice with a filter that is typically used on robots. Their eyes and mouth look mechanical too. So despite the name, they might be mechanical. Or they have mechanical parts.