I'm pretty sure had the regional organisers 'asked' each club which tyre works at what club there would have been an answer and a range of tyres available for certain conditions... And 'that' tyre is different for everyone (certainly at SHRCCC at least...)..
I'm not that good a driver and I openly admit I need all the help I can get on the 'right' tyre front, and I find driving more frustrating when I'm spinning out on a certain tyre when I know otherwise I'd have much better grip..
And like I said, thats why I'm not partaking...
simple really....