thomas and friends mini series

So I noticed something the other day: there's a definite hierarchy of engines. With the exception of bags 65/66 in Wave 4, and the DC engines that were apparently tacked on later, the engines within each wave follow the exact same order. The 3-packs also use the same order: the first 3-pack has engines 1, 11, and 19; the second has 2, 12, and 20; the third has 3, 13, and 21; and so on. Here's a matrix of their order and 3-pack locations:

The 8-packs, on the other hand, don't seem to follow any obvious order. So I think one person (or team) with a lot of attention to detail may have created the line and 3-packs, then someone else (who didn't have all the original information) did the 8-packs, DC engines, and was responsible for Wave 4. Another possible explanation for the strangeness of the 8-packs is that there were originally supposed to be five but someone nixed the last 8-pack (presumably the missing 8-pack would have contained Golden Thomas; that would also have put 76 engines in blister packs, or one more than the entire range, so maybe Dirty Percy was originally slated for an 8-pack, too).