Finish mission A3 with both Wolverines alive for this achievement.
I recommend staying somewhat ahead of them to clear away the Covenant in their path. Don't run too far ahead though because then the Covenant won't be there. When you hear that the Wolverines are taking fire go back to them because most likely some Covenant have spawned up behind them and are damaging them.
Unlike I first understood the achievement it seems that the Wolverines do not need 100% health at the end of the mission for the achievement to unlock. Both of mine had around 50% when I finished the mission and I got the achievement.