Allow me some clarification regarding crew size which, unfortunately, is a can of worms.
The Making of Star Trek
is specific that the Enterprise
was, indeed, to be considered to be a much smaller ship with a crew complement of 203 lives.
Once they had settled on the actual size of the ship (around 1,000') they forgot to upgrade the screenplay to reflect the increase in size, thus the Pike Enterprise
got stuck with only 203 crew members.
In TMoST Gene Roddenberry explained the increase of number by having "expendable" mission and planetary specialists aboard that would be left behind on a new planet for survey and examination. Instead of having the ship return each time to a port to replenish crew personnel, they could theoretically deploy 227 people on planets and elsewhere to keep the crew strength essential to control the ship at 203.
Unfortunately (I can imagine Bobby Justman throwing fits about this inaccuracy
), they changed that concept by the time of "The Ultimate Computer" where suddenly 430 people were required to operate the ship.
Unfortunately this onscreen and canonical information abolished Roddenberry's (good) intention and leaves us stuck to come up with an "in-universe" rationalization why the personnel strength had to increase in a time period of 13 years from 203 to 430...
This doesn't really suggest a technical evolution if you require more and more people to run a starship unless the ship starts to fall apart and requires constant maintenance and repair (unfortunately that's not really a sound theory, either, because we had much more crew personnel roaming the ship's corridors in the first season in contrast to the third, where the ship often appeared to be deserted!).
Apparently they decided to cut down production costs for extra actors but forgot to adapt their "in-universe" crew strength.
Looks like Starfleet had a good idea when they authorized the M-5 computer research. Maybe the M-5 could have been kept under control, had they only intended to reduce personnel back to 203 and not just 20.