Everything Counts

This totally should've been named, 'A mine is a terrible thing to waste'.

This achievement is very easy to complete as a rogue or druid, you can stealth to the kobold/opposite faction boss at the end and solo kill them very easily, thus controlling the mine.

This can be done to each mine in just a few minutes making it easy to get both before the game is over. Simply stay at one mine and have another player guard the other mine to prevent the opposite faction from taking it before the game is over.

If you're in a premade/group with people going for Battlemaster, it ought to be easy to get this achievement.

You can heal your own faction's "mine mob" and if you've got a good healer or two guarding them, it would take a serious attack to take the mine. I'm sure that even with this Achievement, no one will try and mount a proper attack on the mine and foresake a possible victory.