sorry - but I don't follow your reasonsing at all.
first, cassel and brown barely played during the regular season since they were acquired very late in the season. Eddie House wasn't acquired for cheap - he just doesn't have a lot of value, and for a good reason. He's a good shooter and that's about it. Not even close to Kapono in any respect of his game.
there are many reasons why orlando had a big jump this season. First, and foremost is their coach. Second, Howard made nice improvements under Van Gundy, not necessarily in skill, but in how he plays. He got more focused on defense and other areas. Personally, I think they had better luck compared with the previous season.
Atlanta will be better for sure, but not by a large margin. There just isn't any example in recent history where a team made a major jump without new players or a new coach. They had 37 wins, they might get 41-42.
Milwaukee will be better next season, that's for sure. They have a good coach and a nice new player. I think they will definitely be a .500 team and fighting for a playoff spot.
But then again, I see ourselves winning 52-58 games next season. So missing the playoffs would be kind of impossible, unless something really goes wrong.