I feel like the only reason the Wombo Combo and Firebolt nades became prominent was because of how much more effective there are in 3v3 matches, especially Trials. Teams usually stick together and try to control a specific area (which is usually not that big) so a well placed grenade could wipe out the whole team. In 6v6 playlists you hardly ever see anyone dominating a match with the wombo combo or being a self rez warlock. Bottom line if this problem only exists in 1 type of game mode and not the Sandbox, maybe the problem is with the game mode.