Are you saying the panels are too big or too small? You want them small enough to give the impression of size (spec is about 170 m), but large enough not to clutter. Standard steel plate (if that is any consideration) comes in 8' x 40' (2.4m x 12.2m) sections.
For this era ship, I like the idea of people being almost clueless about interstellar travel and basically strapping a fusion reactor and cannons to any kind of tin can that will hold oxygen. The ships should be fragile, incurring wear just from space flight. Markings should be large and bold to promote morale as the ship leaves Earth's space dock, but unmaintained during its duty cycle. I like the idea of these things being part of the 72nd battle group, that being their estimated life span in battle. . . 70 seconds. Surviving ships only a result of a safety in numbers mentality, essentially making it a war of numbers. I like that the specs for the ships have the decks rotated 90 deg. from other Trek designs, but think it would be even more interesting if gravity generators were not yet in use.
As far as other models from this era. I have a problem with the outboard warp engines being present on some, but not others. I am considering that if I do additional models, I will leave off, or have an optional set of outboard nacelles (as if they were upgraded to supplement the Federation's fleet).
The Starfleet Museum site says that the Andorians and Tellarites were allies to the humans. It has been speculated that the Tellarites are responsible for the command saucer module design philosophy seen in Federation ships. Perhaps the Andorians were fans of the outboard warp nacelles (ignore Cochran's Pheonix for this theory). Bla bla bla . . .