Meh armor is the easiest thing to use in my opinion.
- Don't go into urban areas, that's the infantries job.
- Sit as far back as possible so you don't get 1 hit by AT.
- Try to have a 'infantry shield', I don't mean sit 100m behind the infantry but sit far enough where you can engage effectively but theirs infantry from your 9 o'clock to 11 o'clock or even better almost all around you (not right beside you, they could be 1km away). This way anyone trying to flank you will probably be spotted and thus marked on the map.
-Don't stay in the exact same spot for a long time.
- Prioritize against enemy armor and AT. Enemy tanks are usually distracted racking up their kills on infantry.
- Don't go lone wolfing your a support element.
- Turn your engine off if theirs CAS, they don't see you on radar
Do that and your guaranteed to last the whole game if not most of it. You may not get as many kills but you'll guarantee friendly infantry isn't getting pounded by eanemy tanks and if they're getting pounded by infantry they'll mark them. Move strategically and engage.
TLDR: Treat a tank almost like CAS/mortars and you lower your risk of taking a missile to the face but can provide overwhelming firepower when its most needed.