How come the reserves have changed leagues for next season?

It's a higher level of competition and with more teams than the Kent First Division. Worth looking at their website - http://www.sfl.leaguemanager.biz/

Kevin is correct, the club decided to move reserve leagues to hopefully find more regular games and a better standard, this season that should give squad players, younsters and players who maybe need games after an injury the chance to have competitive games.

Up the Mead :-)