I must say that I dont use coach Parrot ,so I dont know anything about that.
No its not a simple feeling its my own experience,I have trained my players to Dutch NT this way.
Now I have 3 Dutch players in our NT and all of them I trained OD first and later JR .
I did this also many seasons ago with player JP Stienstra ,and he came to 100 caps for the Dutch NT .
There are many managers using this "trick" ,and we advice Dutch managers to always train OD first and JR later.....And it works:)