The problem with not killing more than you need to can't be easily fixed either, due to PercentageKilled including captured units. Capturing too many gives you Dread, releasing them subsequently, Chivalry. So again, that is kind of silly.
Similarly, not killing more than you need to in a field battle scenario only applies to infantry armies, not to missile or cav ones. I suppose a lance in your face isn't as chivalrous as a sword or axe?
As for that < vs > sign, I think that was me saying so.

So the problem that remains, if that you cannot check for whether its a siege assault vs a siege sally and that the triggers and traits still don't make much sense