I find that in authentic videos of making matcha (ones made by japanese people themself) that the preparation begins with mixing a bit of matcha powder with water and then whisking it (see 1:46 of this video for an example). My question is what exactly is the reason for doing this? 
A KitchenAid  mixer does not have adjustable gearing; at low speeds it’s being run at low power. If run at low power with a viscous, resistant load like bread dough it can end up stalling, either continuously or repeatedly during the knead. This can overheat the motor and reduce its lifetime. 