Death Structures

Well, if these are Chaos Dragon-aligned neutrals, there could be a lot of them... but neutrals attack in separate groups, and when they try to take down one hero with three groups at once, they often end up attacking each other. Besides, I won't deploy heroes against ten Chaos Dragons without the Combat skill. And to take down a Grand Master (a Master will do too) with a single blow, the dragons need a Tactics skill. Of course, Tactics will only be available when playing against a live opponent – a human. And the human will, firstly, have few Chaos Dragons, and secondly, my heroes will already have the Combat skill. There won't be any panic about letting Black Dragons near the heroes. One strong hero (e.g., a Ranger) can stand guard for a weaker neighbor (e.g., a Necromancer, who might only have Combat skill level 3).
And in general, don't you think that discussing tactics for a specific monster – the Chaos Dragon – in this thread is somewhat off-topic? We're all talking about the overall development strategy for the Death faction. Specifics are important, of course, but the discussion isn't just about them. :)
Actually, I had a question that I'd like to get a qualified answer to – is there an effective tactic that allows you to avoid problems from keeping poisonous creatures in your castle? They're all so slow, like skeletons. And playing the Death faction with a "living" branch doesn't negate the importance of playing quickly... you have to find a way to adapt!