I am looking at this achievement and the way it is worded leads me to believe that the achievement should be counting all victories across all grand companies. Now, I am not the only one who thinks this as I've brought it up to quite a few friends. The achievement, for those not familiar with it reads as such:

"Guide any of the three Grand Companies to a TOTAL of 200 Frontline Victories COMBINED."

Im capitalizing those two words because that is what is leading us to believe it should be a cumulative property. I believe I have a firm grasp of the English language and this is either a bug, or way too wordy and needs to be fixed.

Also, just as a side note, it is only giving victory credit towards the Grand Company you're currently listed in (as if that was not obvious by this post).