Stock ai system - if you look in the gameguru-files-scriptbank folder, you'll see a set of scripts with the prefix 'ai' - these are the ai scripts that use GameGuru's hardcoded ai system. The characters you get with the original version of GameGuru, and some DLC characters, use these scripts.
In order for a custom character to use these scripts, they need to be set up correctly. Each GameGuru model has an associated fpe file, which has a list of properties. Models and all their files can be found in the entitybank folder. Characters using the GameGuru ai system need to have ischaracter set to 1 (if ischaracter is 0 then the model will ignore all the GG ai functions and commands. If you open one of GameGuru's stock characters FPE files, you see at the end of the file a list of animation frames - here's a few of them just to show you
;AIAnims
csi_relaxed1 = 900,999
csi_relaxed2 = 1000,1282
csi_relaxedmovefore = 1290,1419
csi_cautious = 900,999
csi_cautiousmovefore = 1325,1419
csi_unarmed1 = 3000,3100
csi_unarmed2 = 3430,3697
csi_unarmedconversation = 3110,3420
csi_unarmedexplain = 4260,4464
csi_unarmedpointfore = 4470,4535
csi_unarmedpointback = 4680,4745
csi_unarmedpointleft = 4610,4675
csi_unarmedpointright = 4540,4605
csi_unarmedmovefore = 3870,3900
csi_unarmedmoverun = 3905,3925
The numbers are the animation frames. If you have a model that has a walk animation from, say, frame 1 to 100, then you should change csi_unarmedmovefore = 3870,3900 to csi_unarmedmovefore 1,100 etc.
This process is very much trial and error, as the scripts don't tell you which csi_animations are being called. The characters also have ton of animations which aren't used.
One way of figuring out which animations are playing is to add the line Prompt (GetAnimationFrame(e)) underneath the _main(e) section of whatever script you're working with, and use one of GameGuru's models to test the animations - this will give you an on screen display of what animation frames are playing. The display will change rapidly, but if it's a looped animation, you get a good idea of what the frame range is and then match it to the csi_animations.