WarKirby
Arty person
I might be able to adjust things so that if it has no units who are flagged for defense it is willing to flag ANY unit for that purpose who has a combat strength, and if it has none for exploration the same (only if already defended). But I'm not sure that section of the code is easily manipulated in such a simplistic manner.
Instead of just for defence, would it be possible to flag a unit as "inadequate defence", so that it will do defensive duty, but the AI will see that it's not fit for that job (ie, a scout), and will make replacing it with something better a top priority.