I think everyone will learn this map offensively in time. Like anything that's new it takes some time getting used to. Right now the defenses have found their niche in the map (like where sentries go for example). So now blue team will start using their ubers effectively to take out whats needed and where. Also I've gotten through all 3 stages before, and I strongly believe its an uber heavy map. Now that people have their achievements we are back down to 1-3 medics and that just won't cut it. To be an effective offense on this map you need 4-5 ubers imo.
On a side note, just like in dustbowl, people fail to rush to the point (cart in this case) when teammates are using ubers. If you see an uber go off or have a planned one to go in, follow them, you can help take out sentries and other enemies as long as you stay behind them, just use the two invincible guys as a shield. Almost every uber I see used, or am a part of is really wasted. Sure I might go in, kill some people and then thats it... me and the medic are usually toast when the uber is over. Everyone needs to follow an uber in, thats what really makes a good team.