I never played the game but watched some trailers and gameplay videos. I’m 99% certain that Helldivers 2 is following the Starship Troopers formula and purely making fun of patrionism, propaganda, war, the military, military personnel, “freedom”, heroism, politics and military advertisements and turning that into a game. There’s just so many obvious signs, it seems impossible to miss. In other words, it is a political game. Or maybe I just really don’t get either of the two.
In my experience the most popular and fun “party games” are boardgames such as Top Ten, Time’s Up, Hot & Cold or Codenames (more or less in that order). They work best for 6 to 10 players. Though I don’t think they shine in a highly competitive tournament setting.
Randomness exists in all of these games but I consider it very balanced/smoothed out so it shouldn’t really affect the outcome. Not all of the games I mentioned have permanent teams, but that can easily be changed with house rules.