Well its just theory and judging units just by stats is senseless, according to this support units would never be good. I would never choose you units accroding to these table
I dont find archdemon so powerfull ... hes goood against red/black dragons but at other fights there are way more better units than him. And also there are items and other features which change units power for example snakes with frog feanora and snake ring became very powerfull units