Regarding "Combat" and related perks.

"Combat" skill like "Sorcery" is not a good skill on its own.
It is meant to complement other Might skills just like "Sorcery" increase efficiency of magic schools.

"Combat" retaliation values are low because they stack with multiple bonuses from various skills and their perks such as "Defense", "Offense", "Luck" ,"Leadership", primary skills like "Attack" and "Defense". You can even throw "Enlightenment" too because it increases "Attack" and "Defense".

Throw in the following perks - "Critical strike", "battle frenzy", "Retribution", "Vitality"

Damage formula in MMH55 will be:

damage*[1 +(attack - defense)*0.0333]*(1+modifiers)

Lets say attack/defense difference is 0 which it wont be if fighting against mage.

Modifiers are as follows:
Expert attack = 0.2
Retribution (with leadership) = 0.125
Expert luck with critical strike ~ 0.25
Expert Combat ~ 0.25

Lets put them into the formula:

100*[1 +0*0.0333]*(1+0.2 + 0.125 +0.25 + 0.25)
[100*1*1.825
182 damage

Defense and vitality significantly increase survivability of the army so it stay longer and retaliate longer; Leadership passively increase initiative of units so they can retaliate more often. So the actual efficiency increase is way way more than just the 82% that are seen above.

All those bonuses are received by the Might hero army for free. All seven stacks benefit from them from start to the end of the battle. Meanwhile the hero is free to cast magic or do hits to further cripple the opponent or increase the efficiency of his own army.

I really do not understand why you consider Combat weak. Yes it may not seem good pick early game, same goes for Sorcery and Occultism as they are bad without any school proficiency. But this is why Combat offers the "Hero melee" perks which do very well on their own.

During the making of the mod we wanted to make the might heroes to be able to hit harder than the mage heroes. Unfortunately it was not possible because it was a single value in "default stats" for all heroes. This is where "Combat" perk "martial arts" came in play.
It increases Might hero melee damage by 50% which is further improved by the level bonuses granted by the "Chain strike", "Avenging strike" and "retaliation strike" skills.

Note: This damage is even further increased by "Avenger" perk tree. Sylvan, Ranger class is amazing when it comes to sniping creatures with the hero.

The "Armored spikes" perk is meant to strengthen the efficiency of retaliation this is why it gives both "attack and defense".
I cannot comprehend how the bonus for a certain perk is considered weak or strong without first matching it to the whole picture.

Nargott regarding the changes you want for a shorter game.
Shorter game does not mean that when the heroes will meet they will be low levels.
The shortest game I have played was on a small ARMG map with "very strong" monsters setting where player A and player B start in their own zones and there is one high tier zone that connects them. We went for very early clash and our heroes were as high as level 12-13. It just cannot get lower than that because players get those levels by cleaning their zones.

By going outside the native zone and killing some units the hero gains up to level 20 with quite a pace. Mid length games (month 3-4) heroes are 20+ level.
Actually Combat "hero melee" damage is very good for small maps. When heroes meet at early they have not yet started to mass armies and your hero is actually level 12-15.
Combining "Combat" with "Balista" is good early game strategy for Might class heroes.
There is also a way for even faster maps by removing the creatures guarding the zone entrances.

Open MMH55-Templates.pak and on the connection entry set to false.

Regarding the MassSpell ATB: Waiting for Magnomagus to run the tests. I will drop a message as soon as he drops one to the community.

ЗаинтересованныйЕще не понял зачем церберам снизили скорость, или не снижали?
В дальнейшем я бы посоветовал бы вам взять некоторые вещи из UNIT. Там много хороших изменений, но лучшее это:
-Смена местами грифонов и монахов, гидр и ведьм, медведей и костоломов
-Усиление демонес и церберов
-Ослабление вожаков
-Ледяные драконы
-Имперские лучники
-Усиление драконов у некрополиса
-Усиление умертвий

Thanks for the mention!
One of the Cerberi upgrade has speed reduced by 1 but hp and defense increased. Some kind of more durable version of the cerberi. We did it to add some variation as they were so similar they did not offer any strategical choice.
Regarding the "UNIT" mod, we really try to keep the original spirit of the game so we don't want to change any graphics or swap units. The only change in this department we want to do is swap Wraiths to Death Knights but for this we need 3 custom 3D models that fit Necropolis units theme and colours.
"UNIT" mod teleportations effects are from other in-game mechanics and does not look good at all.

All other balancing stuff you mention are already made - second bone dragon upgrade gets 10HP, Red dragon HP is reduced.
Check all changes here -> http://heroescommunity.com/viewthread.php3?TID=43668

I did not check "UNIT" mod balancing thoroughly but I noticed that one of the Haven archers damage is increased to 6-10 which I cannot justify however I look at it.
Just imagine what this stack will do in high numbers, probably even higher damage than Executioners with tripple strike.
This change also makes me doubt the relevance of other balancing alterations. I will check it out the next few days when I have more time!

ЗаинтересованныйИ можно ли усилить атаки героя этой способностью?

If Nargott command exists in Quantomas version of the mod then it is possible. However we have already increased base hero damage somewhere between 50 - 100%.

battleredcatdo you have mode like UVH unique visual hero for 5.5 or something like this, i want have unique visual for hero.

If you want to have a custom model for each hero is just impossible work. There are 8 factions with 3 classes with 6 heroes ~ 144 total heroes.
We considered adding custom visuals per class but we came up to the idea that we either add for all classes or none because it did not look good and we do not have 18 professional models.

However Psatka's mod looks good! Do you know how many custom models there are inside?
If there are enough for every class and they behave well on the map and inside the battleground we may implement it.

battleredcatЕсть ли какая нибудь модификация для 5.5 в виде уникального внешнего вида героев ? буду очень благодарен, недавно нашёл пак героев на другом портале, но там слишком много багов, спасибо

Could you provide link to this mod and some screenshots of the characters? I will forward this to the design team to see if they can make something from it.