Ray, interesting concept for your diorama. The interaction of men and horses is key to telling the story. But there should be some sort of "hook" - something to tie everything together, as opposed to just a bunch of guys in the same place at a particular moment, for no apparent reason. "Confused at the Intersection". "The map is upside down, trooper!" [pile of rubble in background] "The tavern should be right here!" Something, anything to grab the viewer's attention, and focus the storyline where YOU want it to go. Make sure that sight lines are not parallel with the base sides. A slight hillside (front up towards back) might give you the opportunity to show every horse/rider in one glance, without the ones in front blocking the ones in back. Focus on the figures first, but keep the story running thru your head in the background, so that as the figures get built and painted, you'll form a solid idea of how they will be based.
This will be my 20th MFCA, and it is the best weekend of my year. The Committee do a great job of assembling an excellent vendor hall, as well as a diverse selection of the world's best miniature figure artists. You will pass thru a range of emotions as you see the work on the tables - "I would love to do that figure", to "What a great idea!", to "Holy crap, I'll never be able to do that...", to "I'm breaking all my brushes when I get home", to "What a great conversation with _____ - he gave me some GREAT ADVICE!". Take as many pics as you can. Talk to anyone passing by, especially when you see a piece you like. Go to the Hospitality Suite each night, and talk to whoever's there. Soak it all up.
Just one word of advice - stay clear of anyone in a loud Hawaiian shirt, especially if you see a group of them in the SAME shirts . . . Don