Come on, Chris.
Ok, I'll have a go.
Middlesex
Surrey
Warwickshire
Yorkshire
Lancashire
Nottinghamshire
They are your 6 certainties because they have the grounds which generate the revenue which sustains the game (and the establishment) in the rest of the country.
Say goodbye Durham (test centre), Hampshire (probable next test centre), Kent, Worcestershire, Derbyshire, Leicestershire, Glamorgan, Somerset, Sussex, Northamptonshire, Essex, Gloucestershire because the only way the top players will gravitate to the top teams is by making the top division permanent - i.e. no promotion and relegation.
Not a pretty sight, is it?