Well, the use of an AMT model kit wasn't to represent a different class of ship from the Enterprise, it was used to show that the two ships were of the same class. Further, if the differences of the AMT kit are enough to represent a different class, then one would have to say that the Enterprise herself is a Transformer as she went from 33" to 11' to (AMT) 18" versions on the screen. After all, in the second season an 18" AMT model replaced the original 33" model. Usually when people aren't able to wrap their head around things it is because they are unwilling to open said head to anything other than preconceived notions. Unlike the US Navy, which gives out numbers according to ship type (so that any number of ships can have the same hull number as long as it isn't the same type of ship), Star Fleet assigns a new (and unique) number to each new ship. To assume that these numbers have to be in order or even near each other... specially looking only at TOS by itself, is pretty far fetched. Even without seeing other Star Fleet ships, one could envision that maybe these ships take a long time to build and that there would be a vast number of other ships built in between the commissioning of each new Starship. Think about it, what numbers do you guys think the carriers of the Nimitz Class would have if the navy used a unique number for every ship built? If the Nimitz (with it's number from this type of numbering) came along side the Bush (with it's number from this type of numbering), would you guys be making the same wild statements that you are about the Constellation and Enterprise? The Nimitz and Bush would have numbers that would differ by hundreds, so are you saying that you wouldn't be able to wrap your head around something like that? Why not? We had three numbers associated with three ships, only two of which were seen on screen as being Starship Class. Based on that, pretty much all other numbering ideas that attempt to apply some additional logic are wrong. And attempts to change what we saw in TOS (like calling the Constellation some other class) to make bad concepts work is worse than just not attempting to apply ideas at all.