Start with the RTS Prototype - that'll get you making AIPlayer objects that you can control. http://www.roostertailgames.com/TorqueR ... otype.html
Also, look at the AI Tutorial scripts : https://github.com/RichardRanft/AITutorial
- they'll show you one way to make your units think, attack, work in teams, and communicate.
Recast/Detour is built into T3D - so you have a nav-mesh available if you need smarter pathfinding. The way the tutorials are set up the units will run into stuff and get stuck sometimes, but if you generate a nav-mesh and use it to generate paths, then tell the units to follow those paths, you'll be good to go.
AIPlayer is networked automatically - you create the unit on the server and everyone sees it. It's magic (unless you really want to spend some time reading networking code....).