Rush and Breakthrough Balancing

I played quite a bit this past weekend and noticed everyone saying rush was near impossible to win on attackers. Heard of about 2 wins and well over 100 losses while talking in game. I played alot and only had one win as an attacker which came on a smaller scale game. Breakthrough had the opposite.  Defense was a near impossible task. Is this because everyone is using the base guns/kits and will improve as unlocks and progression happens or does this need a bit of a rebalancing?