I have a Rink grip in xl and would say it fits reasonably well, I used the chart on their web site to work out what I would need. I don't think their sizing is much smaller than other grip makers, maybe just a different feel?
Don't you have a stockist nearby to try out the different sizes?
Surrey Guns stock Mannel grips which are also very good. Mannel have many more sizing options compared to Rink so you might find something more suitable there. I have recently changed to one of these and found it more comfortable than the Rink and very well made.
If you can it really would be best to go to a stockist and try a few different sizes.