Improved balance.

Regarding paying troops, this idea has already been discussed for the WGE mod. After careful consideration, it was decided to abandon it, as it introduces unnecessary economic complexity to the game. If you want serious games with complex economies, Heroes is clearly not the right genre. And to avoid hiring mega-sized armies, it's enough to play in a dynamic style, i.e., focus on speed – reach the opponent in 1, 2, or 3 weeks, instead of wasting several months clearing the map. This is where the potential of heroes as a strategy game should be revealed, in my opinion.

You yourself said in the neighboring thread that Heroes should have some resemblance to reality, i.e., resemble a military strategy game. Paying troops, in my opinion, is exactly what is needed to improve Heroes. It is not a complication; it's just that it doesn't suit some maps. You could add a button in the menu before the game and in the editor to give players the choice of whether they want to play with troop payments or not.
By the way, in the games that were the predecessors of Heroes, there were only two resources: gold and crystals. Therefore, I also suggest making three resources: gold, wood, and ore. Then, there would be no need to worry about a lack of resources for building.
Regarding events, you are probably right; it's unnecessary.