Originally Posted by
jdorje
Slaying is costlier than sending, plus you lose military population which can take time to replace, draft, and train. Slaying against merchant kingdoms is usually considered bad since they can send another dragon within a wave or so. Of course, that money would go to training anyway.
We slay with our cow as way to bring her (Jem's) economy to bear without the worries of taxation or desertion. However I doubt she can slay faster than their whole kingdom can send dragons.