Place it ingame with triggers, make x seconds blank at the beginning of the game and that's when u place the units where u want them to be or you can just use WEU
i didnt know what forum to post in>.< terrain sounded best because you place units in the terrain do you not? but if you could please have an mod place in right forum that would be great
You can use the no-limits thing in Grimoire to overcome the 512 unit limit.
However, it may not be very smart as you might shoot your initialization thread with too many units.
That can fuck up your triggers (ie your triggers wouldn't be registered at all).