If I'm being honest, I don't mind the 12 in each leagues we have now.
The problem is more the systems for p&r, and the league.
I would personally change it too.
Get rid of the Magic /Summer bash weekends. They're adding nothing to the game, and aren't even being used for what they were brought in for.
(This applies for both leagues), the 12 teams play each other home & Away. Then split, with the top 6 in both divisions playing 1 more game against each other (3 home, 3 away). The bottom 6 will play there extra games against each other. All sides keeping the points gained at the split, and carrying on from there.
Top 4 in SL play off for the GF. 12th team relegated/top of the championship promoted. 11th team joins the championship play offs, away to 2nd place team. 3rd v 4th the other semi. Winner of play offs in SL.
Bottom team in the championship relegated to league 1. Winner of league 1 promoted. 11th placed team in championship joins the league 1 play offs. Same format as above.
Oh and ALL SL SIDES (AND ASPIRING SL SIDES) MUST HAVE A RESERVE TEAM.
The money argument really dosn't stack up, if Keighley and Halifax can run teams when they don't get as much revenue from TV etc. Anymore.