This is what makes things interesting. To be clear those fish do not look "stunted" but I would bet the RW is low. The pond also looks clear (as in not particularly fertile) and no supp feeding and low forage as per your post above. With those conditions in an existing pond you normally don't get from 2in to 12in in one year. This is especially the case where there are multiple year classes of LMB present. It is possible that the fish you are talking about are the few you put in or they are the best growers out of the 8in year class. However if they were the best growers of the 8in yr class they should not have a low relative weight at this time unless they just finished spawning (15 to 30% weight loss) at one year. I have seen plenty of 3 yr old fish that look just like No. 2 above. My best WAG is there were a few survivor LMB in there to start with.