There is no maximum Championship ave to stop a rider racing in NL, only rule is you can only sign ONE rider who has averaged above 4.00! So technically Edward Kennett could double down in NL (will never happen I know)!
On the Belle Vue vs Swindon comments, I'd expect Bachelor (9.4) to outscore Kildemand (7.5) and Etheridge (4.1) to outscore Rowe (2.9)
Swindon clearly have a stronger top 4, whereas Belle Vue clearly have a stronger bottom 3!
A bit of a guess till teams are completed, but here goes:
1st Swindon
2nd Belle Vue
3rd Peterborough
4th Wolverhampton
5th Ipswich
6th King's Lynn
7th Sheffield
Did Jensen ride at reserve though? He replaced Lampart, who was in the team, and would always have had an ave higher than Perks / Shanes / Wajknecht / Vissing!
1) if a club joins after the AGM they have to follow same rules & could only pick riders not already signed up, this would not hinder any other club as they would have already signed up the best riders available!
2) If there's a large number of riders frozen out from the NL, why not allow another team!
I don't think Belle Vue, Leicester, Kent & Armadale were blocked from entering the NT they only wanted 6 home matches, anyone wanting more home matches could have entered the Trophy I'd bet!
In the past, teams who had only entered the National Trophy (Swindon / Cradley) were able to sign any rider not racing in the Trophy, so if nothing's changed riders from Leicester, Belle Vue, Armadale and Kent could sign for the Gems!