Some way for players to spawn any number of units at any location would be extremely useful for testing. Ideally to do this they would have to enable godmode (server options?) and then they could spawn units via text commands or, to be more advanced, with some sort of UI. This doesn't have to be done now but it would be good to have eventually.
We use control-c, control-v to just cut and paste them. There is also some console commands that can potentially create units. You guys will get access to this stuff eventually but we aren't going to let you do this on the public servers right now