So should I revert it again to the previous state?

Never had a problem myself with animals spawning in City Radius.
But actually I prefer the current solution since it makes "Wilderness" more dangerous and cultural radius less annoying in endgame.
(The
total amount of animals
does not really change - they are just spawned more in Wilderness instead of European Territory.)
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Just make a decision finally:
- Alternative A) Spawning within City Radius / Cultural Radius of Europeans allowed (as before this change)
- Alternative B) Spawning within City Radius / Cultural Radius of Europeans not allowed (as with this change)
Because those are the 2 I can give you within wasting too much performance for animal spawning.
(I do not want to unnecessarily increase turn time because of this.)
Everything else somebody else needs to program.
(And it was never part of this discussion and should most likely be a new thread.)
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Also maybe people confuse
"spawning" with
"walking into".
(2 totally different logics that are not connected to each other.)
Animals can
still walk into Cultural Radius but
not walk into City Radius.
(But with this change they will
not be spawned in any of them, just in Wild Territory.)
So there will
still be Wild Animals in your
Cultural Radius if they
walk into it - they
just do not spawn there.
(There will
never be any Wild Animal in
City Radius though, they can
neither spawn there
nor walk into it.)
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Summary:
It sounds like a good solution that will reduce some annoyance.

It is also performant and was very little effort to implement.
Thus I am not really sure what the hastle is about.