The Melee arena terrain sizes that will be accepted by Hitech are 10x10 or 20x20 sectors.
If you want smaller terrains, build a custom one and put up an arena, then advertise here in the forums to get people in it. Or get chummy with the AvA CM's and terrain builders. None of your ideas which end up ultimately with you saying the Melee arena needs smaller terrains to support those ideas will happen. I don't care about score, whipping it out to justify anything is lame and childish. Do something besides constantly trying to convince the community that you are the top of the food chain when it comes to knowing all to make this game into some kind of utopia. You want to prove some of your assertions, build a terrain showcasing your ideas that are possible within the rules Hitech imposes on Melee terrains. You have always been free to if you believe you have a superior idea. Your last 6 months of pounding the keys to convince us of your superior knowledge you could have finished a terrain and had it in rotation. Then after that gets played on and discussed here in the forums, you might have something to talk about.
The problem with terrains, you have no clue what will happen after the community ups their rides and starts playing on it. All of your cherished assumptions will go right out the window and the players do everything but what you planned for them to do. Until you build a terrain and go through this, you don't have a clue other than tossing around "opinions".