I'm trying to make a computer develop into a town and to guard the town by itself (such as loading bunkers and putting siege tanks), but I can't seem to get it work. I've used some AI run-scripts like Terran Campaign Area Town, Terran Campaign Level Easy, and etc., but they stop working or don't make anything. I've even tried some of the already-placed units to walk around [to make it seem like a town or a village] by using Issue Order and the Junk Yard Dog, but they just bunch up in a little crowd. Any advice on what I should do or check for?

Do they have minerals, geyser(s), and workers near the HQ?

The Custom AI scripts are the ones used in Melee.

Yeah, I put stacked minerals and workers (my map doesnt use gas) and okay

Does the computer have the same race in the player settings as the units you give him?

Yea, SCV near CC and minerals near SCVs

Clarifying for NudeRaider:

Since you gave it terran units and terran AI Script triggers, did you set the computer player as Terran in the "Players" window?

Yea, it was Player 8 Terran with Triggers in player 8, with SCV's, CC, and etc.

Terrain AI under insane usually need about 4000 minerals to start off with. I originally had this problem, but, when I gave them 4000 minerals to start with, they worked fine afterwards.