It's a given that the venues are too small, but if you have to continue to use them in the near future .... remember that it's Disney ... why not issue FastPasses? They work great on the rides. Split the populuar divisions between the venues as previously mentioned and run the International divisions between the US only divisions to help clear out the venues naturally. Then reserve a section of each arena for FastPass holders and issue a limited number of FastPasses for each session like 2500 seats or the entire lower level of the Milkhouse for example. The lower level entrance would be like the FastPass line and the upper level would be like the Stand-by line.
If you have a FastPass, you get to walk in about 10 minutes before that division goes on and you can sit in the reserved section, but when that division is over you have to leave. You can come back in ... subject to seating availability or you can watch other divisions on a jumbo tron. It's not the most ideal solution, but at least you would have a good chance of seeing the division that matters most to you. It might require a short break between divisions to clear the crowds, but I'm sure that could be figured out and the judges and videographers could get a bio-break.
Keep it fair by only allowing each parkhopper ticket to get one Fast Pass per day and limit the number of parkhopper tickets a single individual can submit for FastPasses to 4 or 5 (keeps a single person from getting passes for a whole bunch of people kind of like a single person saving a whole row of seats). If you want to be sure to be inside for Sm Senior then you need to get there early and get a Sm Senior FastPass. You don't even have to stay there all day, you can leave and come back later in the afternoon when it's time for that division. If you are unable to get a FastPass for the division that you want to see, you can hang out and hope to get into the venue sometime during the day and sit in a non-reserved section. If people knew they would be able to get in to watch a division that went on later in the day, they would be much more likely to not camp out in the arena all day which should allow more people to flow into and out of the arenas during the day.
Just a thought ...