is it possible to have differents stuff in zero editor for different eras(kinda like space maps(cw assult and gcw assult))

Yes. You can load any specific ZE layer via lua - glance at the "How to Edit Shipped Maps" tutorial in the FAQ thread and look at the change that it instructs you to make in a stock map's lua. That's where the ZE layers are loaded; you ought to be able to figure it out from there. Or just look at stock luas.