Helldivers 2 boss explains how new Stratagems get made: "We play the game and get bored by the current selection, so we add another one"
The Helldivers 2 devs have a pretty simple process for designing new Stratagems: they just make a new one whenever they get bored of the old selection. That's perhaps oversimplifying the process a bit, but Arrowhead Studios CEO and creative director Johan Pilestedt says it's all about having a fun idea and iterating on it until it makes sense in the game.