I recently played in a decades theme league where you picked a decade and drafted your team. There was a max of 3 owners for each decade. The 3 1990's teams did very well, and the 1910's also performed very well.
The playoff teams consisted of: all 3 1910's teams, 2 1990's teams, and one each from the 1900's, 1960's, and 1970's. Despite their regular season dominance, ALL of the 1910's teams lost out in the first round of the postseason.
I had two teams in the league: a 1970's and a 1980's. The 1980's team was fun but could not hang; finished 74-88, good for 3rd in the division behind two 1990's teams. My 1970's team, despite barely making the post season with a 85-77 record (the worst of the eight playoff teams), made it to the World Series, where I lost to a 1990's team in 5 games.
Hope this helps.