I need help, how to be able to put doodads ones on theOthers

I need help, how to be able to put doodads ones on theOthers

Hi, I am making a nice map and I am putting walls (the normal walls from Summer in the Village). But I wanna make a LOOONG wall, so I want to stack lots of these walls okey? but they are not "stackable". I tryed to increase their size, so I can stack them, and put them together and make a long wall. But it is still not enough, because sometimes the conjunction of some of these walls are more long than what I want, or sometimes they are shortest. So what I want is to be able to put these walls, one on the other, without any kind of restriction, so I can do long walls with the longness that I want.
It would be like "remove" their "physical existence". How can I do it?

Thanks

HOLD shift button and create what you want.

shift+left click = a lot of thing at same place

DAMNNIT YOU ROCK!!!
but if I am copying the stuff? CONTROL V & SHIFT does not work! =(

NVM it does.... thanks man