MMH5.5 - Heroes of Might and Magic 5.5

The specifics of this mod should be taken into account, as it is oriented toward long games (up to 5 months), which is why "Attack and Defense gave too much power." Long game durations disrupt the original balance, so the changes in this mod restore it (in this context).

If the game used to be called "Heroes...", then now I would call it "Armies under the command of...". Because the former importance of hero leveling, which was present in all parts of the game, is lost in the mod (at least on the highest difficulty levels). Now the game focuses on mindless meat (the number of troops)... maxing out a hero means little compared to the size of neutral armies on the map, etc.

Leveling dynamics slow down significantly by the 5th month, so it is logical that the value of troops increases. If the game were oriented exclusively toward leveling, it would not be balanced beyond 1 month of play, as any conceptual build could be maxed out in that time. All durations above primarily serve the troops and the "meat".

The way the game develop is now more similar to Starcraft. It is just as much as fight as it comes to economics.

There is the highest dynamics typical for Starcraft, your comparison is more suited to slow RTS like Warcraft.
According to the concepts of StarCraft, the game would pass something like this:
- Week 1 - the opening, and economic development, capture several towns, capture map zones, and for rushes/harrasment, the main power is 1-3 tier units
- Week 2 - the midgame for the main fight, if both players survived after the opening, the main power is 4-5 tier units
- Week 3 - the endgame, if failed to break the enemy at the midgame, the main power is 6-7 tier units
Delaying the game in StarCraft is not encouraged, but in Warcraft, you can safely and slowly leveling on mobs, with "City Portal" and the warranty to no die by the opponent at this time.
In Starcraft you may lose at the opening easy by rush, because the game supports this, no giving any indulgence to the weaker player with far distance, giant maps with long search, or strong quards.
Starcraft is clearly the game about player vs player, from the very beginning to the end, not about player versus mobs, there is no time spent to defeating large numbers of mobs.

StarCraft is characterized by extremely high game dynamics; your comparison is more suited to a slow RTS like Warcraft.
By StarCraft concepts, the game would proceed roughly like this:
- Week 1 for openings and economic development, capturing several towns and the map, as well as rushes/harassment; units of tier 1-3 hold the main power
- Week 2 for the main struggle, if both players managed to survive the opening; units of tier 4-5 hold the main power
- Week 3 - the endgame, if the opponent could not be broken in week 2; units of tier 6-7 hold the main power
Dragging out the game is not encouraged in StarCraft, but in Warcraft, you can calmly and leisurely level up on mobs, having a "city portal" and a guarantee that you won't be killed in the meantime.
In StarCraft, you can lose to a rush early in the game, and the game mechanics fully support this, giving players no concessions such as great distances, huge maps where it's hard to find the opponent, or strong guards.
StarCraft is a game built entirely on player confrontation, from beginning to end; it is not a game against mobs, and no time is provided for destroying a large number of neutrals.

Magic heroes are more working on their own because they cast magic more often (expert sorcery is 36%) and their magic power can be further amplified (Occultism tree).

This sorcery is imbalanced at 4-6 weeks. Because by this time the armies is not enough much to resist such a magician, especially with 3% attack difference.
It is a good example of how the balance of 5 months is contrary to the balance of 2 months. It's impossible to have a good balance for the all players playing different styles, there is need to choice quick multiplayer, or slow multiplayer, not both. I recommend to add this feature (an orientation for long periods of the game + giant maps) to the description of the mod, since it is very important for the players to understand which style the game is support, quick or slow. Otherwise, playing at normal or quick maps, they will scream that the game is not balanced. Or playing maps typical to mod, complain of too many numerous neutrals.

Such sorcery is OP for durations of 4-6 weeks. Because at such durations, there aren't enough troops to withstand such a mage, especially with 3% attack.
This is a good example of how a balance built on 5 months of play contradicts a balance built on 2 months of play. It is impossible to satisfy players of all playstyles; you must choose either fast Multiplayer or slow, but not both at once. I would add this feature (orientation toward long game durations and large, saturated maps) to the mod description, as it is very important for players to have an idea of how dynamic or leisurely the game is. Otherwise, when playing normal and fast maps, they will scream that the game is unbalanced. Or when playing maps typical for the modification, they will complain about too many neutrals.