What tier is the best tier to Learn game on?

Just a question to the W.O.T. players out there. What is the best tier to actually start playing to learn and to be productive in the game. I am asking this because I have had this conversation with people and I have got many different answers. For me I think you have to actually grind threw the tiers to learn about tanks and there play styles. So starting low and gradually grinding up tiers will actually help people. I say this because I see these people in this game with 40k to 70k games and they play tier 10 and have a horrible WN8 say around 200 to 400 and I see a lot of them when playing high tier tanks 8-10. I mean i honestly see a real lot of these under skilled players playing high tiers where they honestly probably have no business being. Because nobody wants that type of person on there team? I wanna win not lose, winning makes you credits and XP and everything ya need and obviously losing doesn't make ya much of anything besides pissed off. But there is someone telling me oh tier 10 is where you learn and all the other tiers dont matter. I said what you mean they dont matter? I told him if you are a unskilled player and you do no damage or low damage in a tier 10 game you will not make credits, very little XP and it give you a horrible WN8. So he says that doesn't matter that is the tier that matters. But I said no that is not the only tier that matters because you play the lower tiers to understand the mechanics of the game and you need to play them to make credits because if you dont make credits then ya cant even play the game to get what you need. So basically it went back and forth and supposedly i am wrong about low tiers is where you learn how to play the game to learn. So tier 10 is where you learn everything i am told. Can the people here shed some light on this subject? Thanks in advance for your answers.

You can buy tank upgrade them and do your best