Just having an event with more boats isn't going to get more people into the sport. What is the purpose of having a combined event? To promote F16?

If you want to get new blood into the sport then here is an idea which we may try:
Have an event where you must sail with someone from outside the cat sailing group as your crew. Get a 29er, Albacore, 420, or Laser person to crew for you and get them excited about it.