I disagree with idea for using national team for asso. Its enough for me to deal with my main team, i dont want to spend addition tokens, rests and all that resources to hold that national team.
I dont see any complications, if a team is weak, he cant participate in a challenge. If you going to manipulate, you will not play. That's all
This would unlink the league tanking with those teams that tank for FAs, really this was the main solution, discarded now...