If it comes through normal game play, yes.
But I'm not going to do it the way you have done. I'll focus on getting ram kills or defends, but not to the extent of an all-out offensive to get that one achievement fully completed in 12 hours. And I know that's the way you do it, because you're always onto the next achievement the following day.
I'm currently a whisker of L9, and with a chunk of almost completed achievements towards L10. But I'm doing this in regular games and for the most part with PUGs. Because I don't have a clan, and you'll say you don't - but you've a regular achievement chasing crew and an extended occasional high level crew you can call on pretty much every time you log in. That's as good as having a clan, although you don't want to think of it as such. You, Twinkie and Psycho have a higher average level than any clan I can think of, so you can't go blaming it on clans. Is there any clan in the game that has a focus on achievements and levels?
Without checking back at the exact achievements, you'll need four L13 Captains for L13+ DMs. You and Gilder is two L12s to start with - that's halfway there, and I know you're not the only L12 Captains although I can't think of the others off the top of my head. You'll be pushing through L14 before that blocks you. For L10+ matches, there must be over a dozen players that currently qualify and twice as many more that could be there in a couple of weeks with only minor assistance.