Armour, Mobility, Firepower -
Hmmmmmmmmmmmmmmmmmm, ................................ Whrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr, ......................................... Errrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr,
Assumming we can't go with value, build speed, crew survivability, ease of use, reliability, weight, doctrine, complexity, upgradability, access to specialist machinery and/or resources or any of so many more seriously important things that would be the real determinant.
(yes he is REALLY, REALLY annoying when he gets like this, I know).
I'd have to say........... depends!!
Russians - Mobility, then Firepower then Armour - Need to redeploy quickly over large distances and use mass to overwhelme defences when on attack - doctrine and use is based on quantity overcoming quality. Own casualties are least important factor as you will win numbers game.
Western Allies - Firepower, then Armour then Mobility - Shorter operational distances and more crowded terrain mean speed of maneuver is less important, as neither manpower or manufacturing capacity are not a "major" issue longterm priority should be given to knocking enemy vehicles out rather than survivability of chassis/crew.
Germans - Armour, then Firepower then Mobility - Will always be outnumbered in manpower and manufacturing over the long term, need to ensure you get best value out of crews AND vehicles, therefore emphasise survivability then killing power.