You are probably more interested in a "Maker" System,
wich is reasonable for a hobby developer.
In gamestudio you need to still program all the low level
logic for the specific RTS tasks.

I dont know of any available RTS Maker yet.

The only other option apart from programming an RTS is
to create Mods for commercial RTS. But thats less creative
of course.

Here an old Gamestudio Wasteland Demo

http://www.wasteland.at/oldFiles/wasteland_clanwars_prototype_no.zip