The code determines the usage of the forces in various situations. The code determines when the bot uses a particular weapon (something like "if he is weak and up close, switch to bryar pistol" only far more expanded). The code determines how the bot swings the saber, how he blocks and when he blocks. The .jkb file only sets minor behaviors, the reaction time and the accuracy for example. But this won't make a bot to throw a saber and manipulate it for it to hit from behind. This won't make a bot fight any smarter..more lethal perhaps.
The strategy of the fight can't be changed without modifying the source code...plenty of it.