I'm from Brazil and watch closely our national soccer season. One of the reasons we
have relegation is because there's so many teams competing.

The tournament actual format is composed of 20 teams in the main league called "A series". There's more three series, B, C and D. The last four ranked teams "falls" and the first four ranked teams climb up.

I dont know if NFL has enough teams to use this concept.

Regards,
Rio.