This is probably true anywhere and although I have much respect for Tom's breeding program, his Irish studbook has only 16 stallions approved and with 10 of those from his own breeding program he has control over what goes and most of this is an extension of his own program. Poor quality in a stallion is self limiting IMHO, 10 years seems like a long time to wait to figure that out especially if the upfront requirements are not coupled with testing. Possibly the stallions do not breed large numbers of mares and it would take 10 years to have enough offspring to make a judgement. Then again testing does not tell us about the production of the tested stallion and most of the time the stallions that had mediocre results in the test becomes the better breeding producing stallion.
"How many lousy-producing stallions are still being used 10 years later anyway? Come to that, what percentage of stallions in North American are still being used 10 years later at all?
The market is already self-selecting for young stallions, and the idea that breeders are reaching back in the gene pool to select lousy producers is fiction. The model is unworkable (for North America at least, I can't comment on how it would work in a country as small as Ireland)."