Just assume that cavalry represent your mixed forces, same as the infantry and artillery represent their own mixed types.
Personally I love the manpower split and wish something like that could have been done for HoI IV, with Civilian, Military, and Reserve manpower. Civilians would represent your base pool of untrained civilians, Military manpower people who have finished training and can deploy to either fresh divisions or as reinforcements, and Reserves for those that have some level of prior training but are in the civilian labor force at the moment. And calling up troops would use first your Military, then your Reserves, before conscripting the Civilians.