This is what is wrong with you. Go under AI folder and then open bindings.py file and add this:
# 20 - Team Juggernaut
list.append(("AW-Nanowhirl","Spinner",{'nose':math.pi*2,'range':15,'radius':0.4,'topspeed':100,'throttle':130,'turn':60,'turnspeed':2.5,'weapons':(2,)}))
list.append(("AW-Terminus","Omni",{'nose':math.pi*2,'radius':0.1,'range':15,'topspeed':100,'throttle':130,'turn':60,'turnspeed':2.5,'weapons':(17,)}))
list.append(("BW-Microwhirl","Spinner",{'nose':math.pi*2,'range':30,'radius':0.4,'topspeed':100,'throttle':130,'turn':60,'turnspeed':2.5,'weapons':(6,9,10,11,12)}))
list.append(("BW-True Love","Omni",{'invertible':True,'nose':math.pi*2,'radius':0.1,'range':30,'topspeed':100,'throttle':130,'turn':60,'turnspeed':3,'weapons':(12,13,14,15)}))
list.append(("BW-Peer Pressure","Flipper",{'nose':math.pi*2,'range':99,'radius':0.1,'topspeed':100,'throttle':130,'turn':60,'turnspeed':4.5,'weapons':(10,)}))
list.append(("BW-Robokillase","Rammer",{'invertible':True,'nose':math.pi*2,'radius':0.1,'topspeed':100,'throttle':130,'turn':60,'turnspeed':2.5}))
You miss 5 robots out of the slots where the robots should be. I just copied and pasted ant robot team there so rename them and so on.
Then make new folder under AI folder. Name it as Team20 and put there the robots which should be in slot 1, 2, 3, 4, 5 and 6. If you have exported a robot to like juggernaut.bot file then copy it and paste it under Team20 folder and repeat this until you have 6 juggernaut.bot files under Team20 folder. Now rename robots to Bot0, Bot1, Bot2, Bot3, Bot4 and Bot5.
Now you should see the new team when you select new AI robot to fight against. There is only the same robot at each slot because game will crash if there isn't any robot in every single slot.
When you do new robots replace for example Bot0 at your new light weight robot or if you want to do new robot replace either Bot2 or bot5. Bots 1 and 4 are MWs and of course bots 0 and 3 are LWs.
There you go.
Edit: And is this on purpose as "AI\juggnaut.bmp " and not like "AI\juggernaut.bmp"?