According to the fanon-standard 100:1 scale, that makes Collie 6'3" and Mutsu about 7'8". So yeah... I'd say Mutsu is very tall.
I've never heard of that as an actual scale, and it doesn't seem to be very common. If it really went like that then Iowa, Yamato, and especially Saratoga would be taller than any recorded woman in history. Moreover, it doesn't make any sense to make short jokes about Colorado if she's taller than the average NFL player. It also doesn't jibe with the way their relative heights are portrayed in official media; one panel of Tonight, Another Salute shows Gambier Bay and Aquila to be around the same height, even though the latter was over 200 feet longer than the former.
The 1:100 scale works great for most destroyers and cruisers, but it's definitely not a "standard", and yeah, the only people who extend it to capital ships are basically mini-giantess enthusiasts. Still, you get enough mini-giantess enthusiasts who like to flex their attention to historical detail that it's not a rare scale to see used by any means.
Kaktus_Lata said:
It doesn't make any sense to make short jokes about Colorado if she's taller than the average NFL player.
So, a couple of years back the guy behind Monster Musume made some spinoff images revolving around a cow-girl farm (which would later become a plot arc in the main series proper), and one of the cow-girls was self-conscious about being the smallest and flattest girl on the farm, but she was only small by cow-girl standards - by human standards she was still 6 feet tall and would fit a J-cup bra. I imagine 1/100 scale Colorado would be a similar gimmick - around other capital ships it's all Smolorado jokes all day, but then she interacts with the admiral or a cruiser and it suddenly becomes apparent that "oh, she's only short by battleship standards.