MMH5.5 - Heroes of Might and Magic 5.5

With perks like "Battle frenzy" and "vitality" that Heroes V brought you actually can make low tiers catch up with the high tiers. With the MMH55 change in primary skill bonus to 3.33% low tiers can actually match high tiers. So when players are on the battlefield there is no tier that is considered the win factor of the enemy. Now the battle comes down to maneuverability and tactical decisions.

I'm not saying that this skill should be removed (definitely not). But it deviates significantly from the concept of small, passive +2 bonuses, providing a very noticeable boost (in fact, it's an essential skill that players choose Offense for and tolerate the insignificant +5% bonuses).
If you compare Battle Frenzy to Aura of Swiftness, these are skills of approximately equal strength.
Vitality is noticeably weaker than Battle Frenzy, but it is still an order of magnitude stronger than the +2 bonuses.

Lets say you have 40 knowledge and 10-15 spellpower and destruction school:
- During a PvE battle you will get a lot of casualties because the enemy creatures will act a lot of times before you kill them

If spells of level 4-5 are expensive, it means that with 40 knowledge, I can use Meteor Shower and Implosion every turn, while a hero with 10-15 knowledge will quickly run out of mana and have to switch to less powerful spells.
I proposed the concept of 5-10-20-40-80 mana (with an increase in the power of level 4-5 spells as well). With 10-15 knowledge, you won't be able to cast many spells costing 40-80 mana (with Empowered, it will be 80-120, for a single use).
To make sure you understand correctly, this is not about weakening heroes with average knowledge (since the more expensive spells will be made more powerful), but about unlocking the potential for mana scaling and unlocking super-spells for those heroes who have enough mana.
For example, a Fireball for 20 mana can work just as well as the current Meteor Shower for ~20 (if the damage is increased), and Meteor Shower and Shock can be made more expensive, costing 40 and 80, while simultaneously significantly increasing the power of these spells.

where both players build a level 30-40 hero and have army that equals 6 months of time from 2 castles.

6 months with 2 cities is a very, very large army (and levels 30-40 are also very high). It's no wonder that your Magic heroes suffer, and you have to weaken the skills of Might heroes because of them.
For comparison, in a similar PvP RTA, the gains are from 6 weeks of 1 city (!). And the hero levels are around 20, and the maximum SP ranges up to 30.
You have 10 times more troops, and the SP is far from 200-300.

I was just thinking that you are aiming for 3-6 months, not about 6 months (it's not that long). About 6 months means 4-8 months of gameplay, not 3-6.

It is not possible to get 40-50 spell power on month 1. The highest you can go is probably something around 20 on week 4 and this is possible only if you pick Occultism (I have not played in a while so I may be faking the information but it is around that value.). For your information it is possible to go beyond 60 Spellpower in one game.

It's impossible, but 20-30 is quite achievable (for a Warlock with skillful development). I have no doubt about this, because in the original game, I saw levels 20 as early as week 3, since players who play effectively will not wait a long time to reach a high level if they can do it faster. Unless, of course, you have slowed down the experience gain from killing neutrals.
I repeat, for a complete balance test, you need players who are focused on playing quickly, as quickly and efficiently as possible, and not just people who like to play leisurely for 6 months. Try to attract someone among the active TE players.

For my part, I prefer pure PvP lately, and this is one of the reasons why I couldn't be the kind of player who would show you in practice what fast gameplay is like (I haven't played the original game for a long time either, PvE). That is, it is difficult for me to be drawn into PvE; for this, a really cool and well-thought-out balance is needed to make it interesting. And in my opinion, a cool balance and weak skills are incompatible concepts, no matter what you write about accumulating small bonuses for a Might hero of level 30 :).
For example, if there is 30% offense or 30% archery and other comparable passive bonuses, I will say "it sounds cool, I want to try it, there are no such good skills in the original or other modifications, but you have...". This feeling is comparable to a racer who likes speed, but is limited by moving at a low speed only because he is overtaking a pedestrian, for whom the balance is being built.
You will never have this feeling of rapid acceleration due to strong passive skills until Magic heroes suffer and are not able to deal enough damage with spells in a prolonged game (and for this, it is necessary to increase the cost and power of higher-level spells). Because when Magic heroes have enough mana, knowledge ceases to matter, and in fact, the Magic hero must fight with only SP against two parameters, At, Df, and the growing army of Might.

You write about fast matches on week 6, which means either the players are not playing fast enough, or you have some special feature of the maps or fundamental changes that do not allow you to meet on weeks 3-4, about which I don't know anything yet.

Added after 34 minutes

Because you like so much blitz PvP ( and probably other people too) I have an idea of an arena mode where both players build a level 30-40 hero and have army that equals 6 months of time from 2 castles. I believe this will satisfy all the players that prefer battle mode . The worst part is that it is just an idea and is not on the priority list. Of course if anyone wants to start working on this I won't complain

There is a Half-Random Tactical Arena map; you can take it as a basis and rework the scripts for specific skills, and then you will have a ready-made arena for MMH5.5.

Added after 2 minutes
I would like to understand why you consider levels 30-40 attractive for PvP?