Harmony - Troop Symmetry

No. Demons are more geared towards brute force than luck, logically speaking... they should go through combat or chaos...

Chaos magic (Destruction magic in Harmony) already serves as a base for two specializations – for the Elves through three lords and for the Dwarves through the fire branch, and demons don't have much magic to begin with for using chaos. Furthermore, demons already have the "Attack" skill as a path to specialization (Ur-Gash's Call is developed through attack and logistics), so the second specialization will inevitably go through luck; the question is just which perks – in principle, "Hellish Step" (Specialization 2) is a semi-magical perk – the hero's army is always under the effect of the "Haste" spell (+20% initiative), and damage to summoned units is also increased – therefore, the path through the magical branch of luck is not so out of place.
In general, the problem of distributing skills (related to specializations) among races arose due to inconsistencies, such as the "brilliant" idea of Nival to give Dwarves summoning magic on their path to their specialization, when it doesn't suit them in any way. They didn't give them summoning magic in the city (the Dwarven guild is light + chaos, which is logical), but on the other hand, this only amplified the absurdity.
Summoning magic, like any other skill, will become a base for two specializations, but now it's not the Necromancers and Dwarves, but the Necromancers and the Elves (the Elven guild is light + summoning)