The swing isn't the problem for countermeasures as much as the fact that it's randomly swingy. You can't really deploy or plan to prevent a hail mary because you have no idea what draws are gonna be each turn. It seems like they're trying to encourage people not to give up and still fight for points when they're badly behind, will probably make a difference for 2nd and 3rd places
Except you do. There's 20 cards. When a card is removed, it doesn't go back in the deck and scoring enough to re-shuffle the deck is really uncommon.
It's still not accurate enough to formulate a solid plan around, you are actions are still wide open to being made irrelevant based on the wrong cards coming up, or maybe you'll get lucky and the right ones come out and you'll win. Maybe the shit cards that are hard to do come out for your opponent and you win on the back of him just getting unlucky. Who knows, it's random. Player actions matter less in countermeasures compared to other missions.