I disagree with this, mainly because it will NOT favor small countries at all.
IF you are allowed to naturalize ONE player on EVERY TEAM, it means that the bigger nations get even BIGGER.
More teams => more naturalizations => more players. Simple logic my friends.
However, the general idea of "adding" players to small nations is a good one, but could be done by adding a few foreigners in every draft instead.
I would suggest about 2-5 foreign players in each draft. Smallest nations have 46 natives and 2 foreigners and the biggest nations have 43 natives and 5 foreigners.
The foreigners come from random nations, where the smallest have the highest percentage.
For a managers own team, it makes no different, player still counts as own player AND they can still reach NT.
But for NT teams, smaller nations have a slight increase in possible future NT players.
Win Win?!