Do you think that undead are stronger than knights or witches? Black Knights will fix that. And is it not an imbalance that a bone dragon is equal in strength to half a green dragon? As for the second answer... it's nonsense. Everything changed with alt-upgrades, especially when you're playing on a low difficulty level, and 300 militia join you – it's a pity to let them go... because you can get them to the city and leave them to guard it. In King's Bounty, reserves didn't interfere, even though there was nothing to guard there... Well, I don't know about you, but in the League of Shadows, I always take: assassins, archers, hags, provost riders, shadow lords, dragons, and sometimes night queens. So, the slots are almost always filled.

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That is, everyone wants the factions to remain unchanged? Then why is WoG more popular than the original?

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It's been a long time since the races needed to be diversified somehow. With mods? But then you have to sacrifice other, also useful, units...