I'm afraid _
HotRod's post_ disproves your argument, if you accept the version of the drawing he posted as meaningful, canonically. Even of you don't, it's ships of classes that happened to include Enterprises, more or less, but not a list of Enterprises.
1. I thought your argument was that the ships were always bigger. Now you're saying they have been embiggened in newer material.
Please pick one.
2. There is no contradiction by newer canon, unless you're acknowledging that the 2017+ productions are meant to overwrite the original material. However, fans of the new "Star Trek Universe" material typically retreat from that view and argue that it is all the same, either via refit or via squinting.
So, overwrite, refit, or pretending they're the same / not caring they aren't? I would say please pick one, but none of those work.
If you view the new material as an overwrite, then it doesn't matter what existed before, so there's no reason for the denialism over the original canon's declared sizes ... especially if you're going to claim they are overwritten when challenged.
If your position is refit, then you're forced to deal with numerous hull-changing rebuilds, which end up logically unsupportable, as previously shown in other threads.
If your position is to squint, literally or figuratively, then you cannot make any objective claims about size at all, because your position is that there is no objective fictional reality to be observed. It's all just an impressionistic representation, thus you have no basis from which to argue.