We should be sure about our guards loyalty, again. Not Ugly and Fat, of course, but the other who are still alive. They know that they were not killed by the dragon, so they could say it. We will ask Fat and Ugly, and ask them ourselves, something that we will do BEFORE we kill the adventurers. We dont want them to flee before we can react. Wer can ensure their loyalty by bribes, like telling them, all of them, that they will be better at our side, will be the first in get any fine gear we build, the first to be trained in the best arts, and the first to get any prize, and of course, they will be our elite. Those weaks will perish, because the world is arsh, and it doesnt allow the weaks to live.
After all that, we will take 1 hair of each of them, and we will take them to the castle, without letting them talk to anyone on the town when we do the speech thing, and the talk to all of them, with an orb for each, or by any means that we have to detect lies, to, again, be sure if they are loyal to us. After that, as they are our elite, we will treat them as such, so they keep loyal.
About the speech thing. If adventurers ask about treasure, we will say its for the town. Any attempt to steal it will be consider as a direct attack to the town. The money will be used to repay any destruction the dragon did, and to train the guard and make better gears to them. This, of course, is a lie, or at least part lie. It will be used to that porpuse, but not all the money, and, if needed to respond about the amount, we will say a lesser amount than the real one. And to ensure that we dont get stolen, we will get some smart spiders to count the amount that get out of the cave, and another group of the amount that get to the tower(like, 5 or 6 per group, and trying to act faster as they can, dont want to be there for a month).
That everything i came up with. Do as you please with it, OP.