Well, you are going to run into the problem that the bots will most likely use other weapons with longer ranges before they ever get close enough to lay mines.
You think?
Because the Engineer class has the mines, and their kit loadout is:
ObjectTemplate.addTemplate USPIS_92FS
ObjectTemplate.addTemplate USHGR_M67
ObjectTemplate.addTemplate wrench
ObjectTemplate.addTemplate kni_knife
ObjectTemplate.addTemplate at_mine
ObjectTemplate.addTemplate UnlockUSEngineer
ObjectTemplate.addTemplate usrif_remington11-87
ObjectTemplate.addTemplate ParachuteLauncher
So the only other thing they could use against a vehicle is their m67 (grenade)
rem *** Add ushgr_m67_AI ***
weaponTemplate.create ushgr_m67_AI
weaponTemplate.indirect 0
weaponTemplate.isThrown 1
weaponTemplate.minRange 15.0
weaponTemplate.maxRange 55.0
weaponTemplate.optimalRangePercentage 85
weaponTemplate.setFiringPose Standing
weaponTemplate.setStrength Infantry 2
weaponTemplate.setStrength LightArmour 1
weaponTemplate.setStrength HeavyArmour 1
weaponTemplate.setStrength NavalArmour 0
weaponTemplate.setStrength Helicopter 1
weaponTemplate.setStrength AirPlane 1
and he could just set the grenade heavyarmour to zero, so they wouldn't be trying to lob grenades at tanks, and then their only choice would be the mines.
I'd suggest also changing the AT Mine line
weaponTemplate.maxRange 30.0
weaponTemplate.optimalRangePercentage 100
because, in my opinion, I want those mines on the road before the tank gets there.