I do not know if "strict" is the right word, to be honest.
I've played a bit around with the system tonight and... frankly, if it was just me, they would be far more bigger.
The 2000 population limit seems more fair to me as it is now (on my code), lifted at 2500, at least.
This is our "neutral" town council tolerance setting.
The "permissive" one, from 800, has been changed to 1500.
And the "hostile", from 4000, is now sitting at 5000.
the 3/5/1 pattern seems to be the most reasonable one, from what i've seen on our side. Don't forget we have a few more airports.
So the other ones would have a bit of an unbalance compared to the ones we share.
So a town of 26k inhabitants would have a noise tolerance of 20, which can give us up to 6 small airports, plus 2 helipads, which is not too bad at all, if you ask me