And here, the author added a note about my request regarding the differences between the English and Polish versions!
And he writes that everything is good, everything is "balanced" :)
09-10-2017 15:54
English vs Polish versions - LIMES INFERIOR

One little note. The new English version of the map is a little different from the old Polish version. During translation, I made some changes. In the English version, it should be a little easier at the beginning (e.g., slightly better starting bonuses), but the Orange and Purple opponents should be a little stronger. I made the changes after analyzing a 160% walkthrough. Now the map is more balanced.

But anyway, the changes are really small.

That's exactly why I concluded that the author didn't test the changes at all. At first glance, the changes seem small. But in practice, this leads to very strong AI development. If I'm not mistaken, it captures Inferno by the second month and has a total growth of 6*3+6*12=90 units per week across all castles. That is, by the standard arrival at the beginning of the 5th month, the AI can assemble a stack not of 200 units, but of 400-500 units. And if 200 units can be defeated without critical losses, but barely, then with 300-350, there may already be significant losses, and with 400-500, it becomes impossible. This is not counting the growth of the other army.

And the funniest thing is that at 130% or 200%, the difference is actually negligible. What can you do additionally at 130% compared to my development strategy in the first month? I'm even afraid that at 200%, my development will be better than yours at 130%.
The AI's intelligence is the same at these difficulty levels, but the only difference is in the increase in resources, and this thing only adjusts the AI's development by about a week or two within the 5-month interval.