[MikeDubreuil]

I can understand your logic that technically the offensive robot could lock onto either target. However, there's more to R31 than just jamming and interfering. There's an example given to allow you to understand the intent of the rule. It says you're not allowed to confuse the opponent's vision system. Having two lighted targets on the field is confusing. Therefore, your device would be intended to confuse the vision system; making it illegal.