I also doubt that there is a reasonable way for a widget to decide what would be "the best idea". If you'd come up with something like this integrate it in an AI please to have an unbeatable enemy...

Deciding what to bomb is a player's decision and totally depends on the situation and should stay that way...

PS:
Similar to Jazcash I have pretty much never targetted metal makers with bombers. That only makes sense if he build tons of T1 makers in one big farm or like 4+ T2s right next to each other what no experienced player would do. As they get useless anyway when you kill the power generators (and as they're rather cheap to rebuild) it makes much your sense to destroy those and kill two birds with one stone...