Weren't Carlisle actually top for a week near the start of the season in 1974? Oxford were definitely a top-flight team for a while in the 1980s. And Northampton should have been another in the 5-divisions club, but were spared relegation from the league in the early 90s because Kidderminster Harriers' ground wasn't good enough.

Maybe the EFL should start being a bit more stringent about grounds this season - you must have a stadium at least as good as the team you are replacing, for example...