@TekNicTerror you are right, it is a battalion mission
a little long if someone play PvE, takes 20 games if a player has on average 10 kills/match, but very fast if the player plays PvP, GLOPS is the better option, as you need only 40 kills to complete it. It is the fastest to complete battalion mission IMO, a decent player that plays the tanks he has to grind once in PvE fro the multiplier then switches to GLOPS most of the times can complete it in a single day without having to play focused on it.