Clearly, Mice and Keyboards are the worse input control for For Honor. But I believe there is a easy way to fix this, disable mice blocking directions. We already have keybinding for the blocking directions, we don't need mice to mess everything up.
Personally i prefer mouse/kb to controller, and i don't want extra keybindings for guard protection over what we already have to press. Though i agree that if people want that as an option, then it should be provided to suit bother player type's requirements.