Roy's dancing blade Side-b works wonders on Richter and Simon. It comes out fast, has range, and shoots people out way farther than it should. If you're on a stage like Battlefield, stand on the edge of the lower platform and try to time your approach in between them throwing projectiles then rush down and hit them with a dancing blade. Both Simon and Richter struggle against characters who can get in on them and keep up the pressure which works well for Roy since he's really fast in both the air and on the ground. However, I don't recommend trying to short hop over his projectiles since Roy's short hop doesn't go high enough for him to hop over anything.