I want to suggest a field troop limit based at 3 and increased by a value determined by the charisma of heroes in the party. Every 3 points of Charisma could equal one point of leadership for the Hero with the highest charisma in the group, with half the effect for any accompanying heroes. For example a sovereign with 10 Charisma would have a leadership of 3, allowing the sovereign to lead 6 troops into battle (sovereign +5 additional units), if accompanied by a hero with 10 charisma, the sovereign would be able to lead two extra units one of which would be the hero.
Such a change would ensure a certain level of balance and actually make Charisma a worthwhile stat to have. It would also have the effect of making monsters a little more challenging, scaling back their numbers would be a good idea, fewer and more challenging monsters would likely increase immersion a bit.
Oh and we'd like the Organized trait back please. Seriously a sovereign with Organized is obviously being placed in danger of lost max-essence or a quick game over so it's not over powered, it's a dare devil's gambit.