Just my take. Others will (hopefully) chime in with their thoughts too.
I personally don’t really prioritise Defence as anything special… This thread sums it up pretty well: Your Defense Team Is Good Enough
As long as you can open your PvP chest up in Diamond Arena then there isn’t really any point in having the best or a “meh” raid defence team…
Wars is something different but from what you said, you rotate thru different colours so ascending a hero specifically for a 20% of the time war tank doesn’t make a huge amount of sense…
So I usually vote for the hero that is the most versatile. Telluria is still pretty solid on offence BUT I hate minions on titans… so she gets a black mark there for me 