As you may notice in most maps, atackers has a great advantage over defence because they can easily dominate the walls even defenders couldnt defend.
I suggest that in the begining of the round, defenders should spawn 10 seconds before the atackers to organize their defence. I'm not sure about the extra time but i think it's a good idea to discuss.
And also it's very annoying to see 5 cons. sites together. There must be an area around cons. sites where you cannot build another one, like ladders.
Thanks for your comments.