Jesus Christ. I'm on Normal Ironman, and I've restarted my campaign SEVEN times now because grenades continually kill 3+ members of my ground forces at a time. Even with good armor, they absolutely annihilate my soldiers, and I have no idea what I can do to defend against them. It always happens when I'm breaching alien ships/bases (sometimes they throw grenades through the ceiling of the ship, that's cool). What the hell can I do? If I send just one or two soldiers in, they'll probably just get gunned down. I guess I'm just encouraged to wait outside the entrance of ships, spamming the open/close door command and waiting for cheap kills. I don't like playing the game that way.
Really frustrating. I don't think I'll be playing any more Xenonauts until grenades are rebalanced. : (