Well, I like your work. These show good shape and form without being poly heavy. Well done.
And I never considered the volume of Constitution to be a possible detriment before. I mean, I knew Miranda had more volume but I figured Ptolemy, Hermes, etc had considerably less. But, thinking about it, you're right. Having opened up so large a volume of the galaxy means you need more volume in your vessel. Connie's own success was the reason for her retirement.
I had attempted to catalog all the different missions the TOS Enterprise went on and it was quite a spread which included cargo runs and evacuations. I can only imagine from an in-universe perspective more trunk space meant more savings in time and money.