My only exposure to the book is from reading Simon Kuper's Why England Lose & Other Curious Football Phenomena Explained (incidentally a brilliant read, thoroughly recommend it to anyone who loves their football), and the premise of the book seems to be the transformation of a small outfit by rejecting what everyone "knows" about the sport, specifically how the transfer market works. The parallel to Morgan is clear: everyone "knows" that a player with a reasonable at best FC record won't be a success at Test level. The case of Morgan (and Collingwood, Trescothick and Vaughan before him, and conversely, Graeme Hick and Mark Ramprakash) would indicate that the conventional wisdom sorrounding a player's FC record, whilst not wrong, isn't perfect either. Clearly, the England management have seen something about Morgan that they believe makes him suited to Test cricket. It happens to a degree in football - Miroslav Klose and Lucas Podolski shouldn't be as good as they are for Germany based on their club careers
Kuper's book is a great read, as is Moneyball. The biggest issue I hold with the parallels drawn between Moneyball and cricket analysis is that Moneyball is built around the analysis of statistics that were ignored, or over/under-valued. Effectively, it boils baseball down to a different tactical business than had been otherwise implemented: Beane wanted batters who took bases, allowed balls, didn't strike-out - grinders and percentage players, rather than the flair players who impress with big hits. There was another analysis with pitchers, but I don't recall it as I don't follow baseball closely enough for the specifics to have had resonance.
It is very tough to replicate this in cricket as players like Vaughan, Collingwood, Trescothick and Morgan do not have any statistics, popular or otherwise, that elevate them above your Hicks and Ramprakashes (and Boparas?) I have tried analysing stats like dot ball percentage, runs in boundaries, or even making up my own stats based on combinations of these, and they have indicated kids who have gone on to really kick on with the bat - but I can't help but thinking I was trying to match the stats to my instincts of the kids who would go on and get runs.
I do think that some of the methodology mentioned in Kuper's book is very astute, and certainly correlates with the way I try to coach the game - I've been playing 4-2-3-1 with the school team for two seasons and will certainly give the book a re-read before the new season in January. Cricket wise I vowed to spend the whole winter working on batting, distilled down to playing off the front foot with a straight bat for the most part, with my County U10s having been sick of losing to everybody everywhere: and we have won four out of five this summer to date.
As for the Welsh question, there is one Welsh sides in the Minor Counties championship - Wales Minor Counties, which is an amalgamation of everywhere else outside of Glamorgan. At youth level, Wales is split into nine regions, who play between one another with occasional forays across the border for the honour of being battered - Tom Scriven of Berkshire U10 took 183* off Gwent last year, and they're usually one of the stronger groups. North East Wales lost to Shropshire by 9 wickets last weekend, with the Englishmen taking 12/35 overs to knock off their chase - and then two days later Shropshire were on the end of a similar hiding from Oxfordshire (this time the total was knocked off with 19 overs to spare). There is also a combined Wales side that play friendlies at U11 and upwards, and in the U13, U15 and U17 competitions - where they won the U15 title in 2007 and 2009 and are currently topping the South West group of the U13 comp this year.