Many clubs in the Thames Valley have merged due to numbers. Alot of clubs now with 3/4/5 teams as resources get pooled and pitches reduce. My old local rivals have gone from 3 teams to 1 and without their Chairman bailing them out, they'd folded by now.
I don't know that there have been *that* many in the ten or so years I've been playing down here, though I know our merger was a resounding success once a couple of bad apples had elected to pursue their dreams elsewhere. I guess you get on top of that a few of these "parent club" arrangements, where biggers clubs such as GX, Datchet and
High Wycombe take on smaller clubs to run as their lower XIs, which works pretty well for all concerned.
I think what has helped the Thames Valley in the last few years has been a combination of Chance to Shine - amazing how well it has done in afluent areas, suffice it to say - and the movement of second and third generation Asian families out of the centre of London, which has meant that some clubs that were once pretty much village teams have become really big units. A lot of clubs around Maidenhead especially have seen their numbers skyrocket!