yes, nowadays I have been doing the same when playing, watching what happens and how own and enemy units react, it can be a great source of ideas, beside reading articles written by rts game developers, and comparing them to my solutions, what to modify and what to keep. (of course it decreases the gaming experience)
it can be 2-3 years for a little programmer team (2-3 (wo)men) to develop a great rts game ai, so what I know is that I can do this hobby for a long time and beside game play programming I can learn the visual stuff too as a recreation. the main problem of the open source rts game 0.a.d. is that they did a lot of work on the graphics, but let the pathfinding and ai in a very unefficient basic level, thus after years it is still not really playable... I hope I can find a better development way.