Countering a attack from a player is laughable with the current targeting system (esp on Controller). You simply have no chance to target on counter on time.

Countering with Guard is even worse because the game often just stops reacting to inputs for seconds when you are attacked by multiple players.

tl;dr: Frontline is basically trash content that most players just play for the daily XP boost. Serious play is nearly impossible, trying to get the achievements is basically a game of chance