I once defended Orsam, and an albolabr came to me with a full set of runes and a devastating zap against all the Necropolis units. Many troops were huddled behind the shield, exposing themselves to the dragon's breath and the chain lightning of the Jarls. It also becomes quite problematic and dangerous to attack the cart, as after teleporting, the skeletons are left alone in the rear and destroyed, and the liches are likely to be blocked. You just need to understand what tactics the opponent is using, and then apply a counter-tactic.

The cart and ballista are killed by a hero. Jarls are certainly scary, but I think when they arrive, there will be no more than 6 of them (they can be hit once or twice by dragons), as they are all in defense. The problem, of course, is killing the dragons, but there is a hero, a crystal, and mines for that. There is absolutely no need to teleport anyone – that's a guaranteed loss. And if you block the liches, there won't be a stack blocking. In general, there's also morale and luck, which play an intangible 20% role, as well as invulnerability and stunning.