[@Expolar]

I like most of those ideas. But rather than having their strength and skill being called into question, perhaps instead it could be the wisdom and intelligence of Clan MacAlister having doubt cast on it. They prove their strength and skill often enough for that to not be questioned, so I think the dragon would have an easier time convincing people that they are a clan of bumbling brutes who charge headlong into the dragon's lair without a single thought for strategy and get soundly thrashed.

Also, if you want any help coming up with something to say about Dachaigh, I'd be happy to lend a hand.