Nargott
Auto-translated
I reviewed some of the artifacts and have the following comments:
Group 90-100k:
1) Angelic Alliance: +12 to attack, +20% initiative
2) Cuiras of the Dragon Gods: +5 to all stats
Group 40-50k:
3) Staff of the Netherworld: -20% initiative (for -1 penalty to Morale)
You are underestimating initiative. 10% initiative ~ +4 to attack (at least). In the new parameters, this is ~ +6 to attack. Your new parameter is worth 5k per unit, therefore, the value of 20% initiative is 60k. The value of -20% initiative = 1/0.8 = 1.25, at least 75k. Against neutrals, this artifact works similarly to +25% to the initiative of troops and +25% to the initiative of the hero (all of this is boosted relative to enemy troops), considering this, the estimate can be increased to 90k, or even higher. A -1 penalty to Morale is a minor detail that can be ignored in this context (especially for mage heroes or undead). Its maximum value is 10k (in the new parameters and considering the weakened Retribution and Empathy).
Thus, the acceptable price for the Staff of the Netherworld is in the range of 80-90k (the strongest artifact in the original game), not 40-50k.
Angelic Alliance: +12 = 60k, +20% to initiative = 60k, totaling 120k (not 90-100k). Why are they summed without penalties (although I penalize for secondary bonuses below) - because both parameters work in the same direction: boosting the damage of troops per unit of time. If you play in an aggressive style, both parameters are equally important.
Returning to initiative, why is it so expensive? You evaluate +6 to attack as +6*3.33% = +20% to damage, although in reality, this is only a bonus to the base damage of creatures (and even then, only if the attack is higher), but not to the total damage. The bonus to total damage will be significantly lower, on average +15% (you can check the calculations for different pairs of creatures with different attack and defense). 10% initiative is no weaker than these 15%, even though the formal DPS of initiative is lower, but initiative provides an important first strike (unlike +Morale, which does not boost the first strike in any way), and also works well with mages, tactical single units, and affects Empathy.
Cuirass of the Dragon Gods: formally, it has +20 parameters (100k), but in reality, this is a relatively weak artifact because the bonus is diluted among all 4 parameters, of which only one is key, the second is less important, and the rest are just for show.
I evaluate mixed (non-synergistic) bonuses approximately as follows:
100% for the first bonus
70% for the second bonus
50% for the third bonus
35% for the fourth bonus
The final estimate for +5 to all parameters = 5 * 5 * (1+0.7+0.5+0.35) = 62k, not 90-100k.
The value of such artifacts lies in their versatility, but "overpaying" for versatility by more than 1.5 times (buying on the market or breaking through a super-strong guard) is too much.
In Random Tactical Arena, the artifact "sandals of the saint" (+1 to all parameters, luck, and morale) is one of the least popular among players on the market, even though they have already started offering discounts for diluted bonuses. The artifact "armor of the forgotten hero" is mainly bought for 20% magic resistance (this is the main bonus), the diluted parameters are just a bonus.
4) Artifacts with +50% to elemental damage, you have them in one group (10-20k)
Firstly, these are very strong artifacts (imagine you have 40 SP, which is not uncommon for your game, and you boost it to 60k for key spells that you cast during a battle). This means that the bonus should be comparable to 20 SP, at least considered as 10 SP. The fact that the artifacts play weaker in a small game is not a justification for the low value, because their maximum value is realized in the late game, and if they are well guarded (according to their value for a long game), then it will be too early to break through them.
Secondly, these artifacts are not equal to each other. Lightning is the weakest, there are only 2 out of 12, of which chain lightning (the highest-level spell) is only level 4 and quite situational (it is not very convenient to use every turn when the battle has already begun). Earth is the strongest, 3 out of 12, of which 2 spells are level 4 and 5. Plus, does it enhance plague (or is it no longer in your mod)?