@Indirik,
While its not very viable to do to cause mass devastation, it could be used by diplomats/infils during key moments (big battles mostly) to the turn the tides expensively. Investing in your army is better, but if you don't have the time for a refit, have everyone basically already maxed out, or want to show off your wealth then it makes sense to do on a rare occasion (which is what it should be).
