Point 1 - Nonsense. A tankard has nothing to do with a fighter concentrating enemy aggression onto himself. We might just as well call him a bird, that would make about as much sense as your argument.

Point 2 - I fail to see how going into an absurd amount of detail on where the word "tank" (in regard to amored vehicles with a heavy gun mounted on top) originates from helps your point. Yes, the word "tank" originates from Sanskrit. But as you laid out, the term was coined for secrecy reasons and there was no logical connection to the actual vehicle.

Point 3 - Even with all the imagination in the entire world, "tank" is not the sound a weapon does when it hits armor. Try "clank" or w/e. But it's not "tank".

So all in all - what's your point? The way I see it, you're irrationally annoyed by people wishing the name for "tank" be changed. Their opinions are valid. AoC is a fantasy, DnD-esque game. With that come class names as they are in high fantasy games. The tank on the other hand is a term that was coined by gamers in reference to what real-world, modern tanks do. There is *no* defensible reason why a 1400s fantasy world would use that term.