I only have to grind this line from 7 to 10, otherwise, I have all the tier 9s in the game either researched, bought, or done with. Nowadays, I keep playing as one of the two tier 9s against five tier 10s in fun game modes, doing what I can. But when I do go back to lower tier, I sometimes wreck the lower tier enemies like it's nothing. Sure, I also fail frequently, but when the stars align, the beginners in their low quality tanks stand no chance. Going from tier 9 fighting tier 10s, to tier 7 fighting tier 6s is like someone with real war experience playing a board game 😂