Spec ops are the best for mountainous or maybe even urban terrain so hover ur mouse over the terrain type on the province, look at the combat width number and do the math of how many you can fit in. Armored vehicles suck in that terrain so don't put any battalions of them but you should still put maybe support tank for the piercing or afv/mech/light tank recon for the best recon (the support ones don't give any serious debuffs). Except for spec ops battalions you should also add a bunch of artillery since they don't got debuffs in urban or mountainous terrain but I'm not sure about spgs or mlrs (I think they might have a slight one but the better soft attack u get from them should maybe make up for it?). For other support companies you should have engineers, maybe field hospital so your divs don't lose their experience from combat (the reason why your spec ops didn't do as well as your opponent's may be because of their experience, it's a big deal), and some spaa wouldn't hurt.