1) Black Knights can be easily purchased in the Chaos castle with the aim of fighting Dragons, since the latter are not immune to passive bonuses. On large maps, this can be supplemented, for example, with Nature for increased bonuses (and spells can be found in the spellbook). The only drawback is that it is not so easy for a Death hero to obtain it, but if a way is found...
2) Archers are quite good warrior heroes who, of course, don't "outshine the Barbarians," but they can certainly keep up with them.
3) And also in terms of magic. Suspiciously reminiscent of the system and philosophy of one card game, it (anticipating events) is created in three colors: the main color and two adjacent ones. And although the range of "neighbors" will not be as rich, in theory, Chaos is an interesting candidate for creating Demonologists, as it provides them with spells from both the black and green halves of the table. And for summoned demons, feline grace and the killer spell of a "specialized" Chaos mage will be very useful.
As a result, the castle has something to offer at any stage of the game, and the range of available development paths allows you to adapt to the features of the map and opponents.
However, there is also a fly in the ointment: Chaos cannot remove negative effects (just as Nature cannot remove "positive" effects), since both Life and Order are "hostile schools" for it.