Heroes 5.5 WarGame Edition - Tactical Edition.

The whole point is that the player shouldn't be sure which of them is stronger, the Knight or the Griffin (competition). Fewer Griffins appear, but they are also easier and faster to build; in the most effective builds, the Griffin often occupies a leading position, while placing Knights in the first position should be less popular (in terms of the number of strong options, and that's how it is now). Specifically, 2/3 of the first-week openings include Griffins, and only 1/4 include Knights. This means that Knights, if placed at all, will most likely be placed in the second week. And as a result, despite the greater increase, there will be fewer of them initially than Griffins accumulated from the first week.

Added 1 minute ago

As for the increases. Don't you strive to make all tiers, taking into account the increases, equal in strength?

No, the main thing is the principle of competitive building; the fact that in some cases there is an equal increase for a certain amount (with the same requirements) is just a side effect.
For example, the requirements for Knights and Griffins are clearly not equal. Knights are placed later and require a stable (which is a tempo cost).

As for competitive building, this is evident in the example of the Dungeon. I set initial values based on a comparison with Humans, analyzed the composition of possible openings, drew conclusions about which tiers are lagging behind in openings (less in demand and less effective), and whether it is necessary to strengthen the faction as a whole; as a result, I increased the increase for Scouts.

Added 6 hours 25 minutes ago
Update: I updated the schemes on the previous page:
1) the shipyard is now available from the very first line (not tied to the city level and castle)
2) Hydras have been moved 2 days later (from day 3 to day 5), while still not tied to the Citadel

Added 9 minutes ago
And the detailed schemes (in terms of decision-making by day):



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