Harmony - Troop Symmetry

It often happens that after level 32, there are no free slots because they are all occupied by skills and abilities. And it becomes uninteresting to play – you level up, but you don't get a new skill.

The peak of interest in leveling up occurs somewhere around levels 15-20, in my opinion. This allows you to specialize and develop a specific build, rather than trying to do everything at once, while maximizing variety. If the games are so drawn out that leveling takes 32+ levels (as far as I understand, this is a consequence of the controversial modification of the leveling coefficient in the modified executable after level 24), wouldn't it be better to simply introduce an experience multiplier, for example, 10%? This is the most logical adaptation for "special" maps that require unrealistically long completion times. Although, on maps with such a large amount of content, I can't imagine what needs to be done to make offensive magic viable.

Let me give an example. Suppose you need to level up a mage on Chaos difficulty, and at levels 15-20, you have these options:
- Sorcery + Chaos + Luck
- Sorcery + Chaos + Defense
- Sorcery + Chaos + Second School
- Sorcery + Chaos + Education
- Sorcery + Chaos + Leadership (Empathy)
- Chaos + Leadership (Empathy) + Luck
- Sorcery + Chaos + Logistics
and so on.
See how many fundamentally different builds there are, and how many skill slots they take up.
But if you level up to 30+ levels, you can grab everything at once, and there is no variety.

6 skills (1st tab) - 6 abilities, 3 each (2nd tab)
In the Hero tab - 1 slot for a racial skill (level 3) + 3 slots for racial abilities + 1 slot for a general skill. In total, you get 5 slots. As in your picture.
Overall, the situation is workable; I think this option is close to perfect. It is better than the original, made by the game developers.

Unless it's for extremely long games, i.e., rebalancing for "incorrect" maps.

By the way, 6 skill slots are already implemented, but 1 of them is racial.
And it can be proven that, from the point of view of variety, this number is optimal.
For example, if you are leveling up a mage, the build can be a mix of 10 skills (attack and summoning skills are not needed; the remaining 10 skills have options for a mage). The same applies to a warrior; 10 relevant skills (Chaos and Summoning are unnecessary, and Sorcery can be useful for a warrior due to counterspell or distraction). And the maximum variety among 10 skills is achieved by groups of 5, which is exactly what we have: 5 slots for general (non-racial) skills. This is from a formal point of view; in practice, the most interesting builds consist of 3-4, rather than 5 skills, as they are more specialized and different from each other (see the example with Chaos above).