Greetings everyone. I have a question in regards to the Esenthel RTS Source. I am actually learning a lot from it, as it is helping grasp a few things in regards to the engine. I am Curious about the order that these files were written. From a beginner perspective how should one be viewing this? Was their a specific code file that we started with first and built from there? If I am to rebuild this for learning purposes where would I start?

I don't remember, but if I were to start all over, it would be:
-display the game world
-display the units and buildings
-allow selecting units
-make units can move
-make units can attack
-make units can harvest resources and build
-make simple AI that can reuse the implemented functionality
-etc.