This might be an embarrassing post of mine. I am not really a Tank expert. But what do you expect when every single one always pick everything else but Tank. Then you just gotta do it when no one else does, right? So I have become a Tank user in Rank ever since Season 6.
My first tank was Minotaur, venture a bit to Akai and Johnson (sucked at it). Ended up with Gatotkaca, other says it is hard to maneuver him, but what if you miss his ULT? Don’t worry you got his 2nd skill to cover up your mistake.
Out of my 7000+ games played, only roughly 1000 belongs to Rank Games. So I am not very experienced. But I do know, once you understand the basic gameplay or strategy or whatever you call it (instinct). You have an easier time to win. It is all about covering up for each other, timing and team play.
Never stick to only 1 hero, always try to play many different. Only versatility can keep you going. To defeat the enemy you need to understand them first.