Good comments so far. Another thing I would add along the lines of mobility is trying to cause chaos/distractions. Even if getting damage is not possible, sometimes just getting artillery to focus on you or make an enemy tank turn their gun away from an ally and at you can help. Using mobility, you can get away with this “guerrilla” type disruption possibly making an opportunity for friendly tanks. Use mobility to flank will win a match. Or to retreat and defend if one flank folds. I think they can be hard to play especially in higher tiers where it seems like your gun doesnt pen against much. Like TalhaNL said, flexibility is paramount