[HoMM V]9 Race - Swamp! Is it needed?

Yes, yes! Create a race that is extremely unpleasant (and stinky!) both in battle and in appearance! I support the hero development. I would replace Chaos magic with Nature magic; it's much more unpleasant.

Easy to obtain: 1) Dark Magic 2) Logistics 3) Nature Magic 4) Defense
Medium: 1) Chaos Magic 2) Sorcery 3) Light Magic 4) Learning
Low: 1) Attack 2) Mechanics 3) Leadership 4) Luck

1) It's not worth changing Chaos to Summoning. The main goal here isn't to make it as unpleasant as possible. It's also easier to balance, and Chaos compensates for the weak (as I understand) ranged units.
2) The essence of the racial skill is that your hero moves more often, and the enemy's hero moves less often. Based on this, the strategy for developing the battle should be:
Easy to obtain - SORCERY (the most important quality), Darkness, Chaos, you can also take Logistics (I think it's logical, but not essential)
Medium - Learning
VERY difficult to obtain (2%) - Summoning, and all skills that increase the strength of units (Attack, Defense, Luck...), because you can't have both a strong hero and the ability to strengthen units. Although, perhaps Defense, due to ideological reasons (it's closer to the swamp, after all), can be made more common...