Everything else being equal, it does. If the only thing different between one universe and another is the maximum size of ships, the same political considerations that produced a military budget capable of support one 500,000T dreadnaught will produce a military budget capable of supporting 100 5000T dreadnaughts.
Hans
No, because everything else is not equal. A big ship universe produces cruisers and battleriders each with one nuclear damper capable of dealing with incoming missile fire. The damper by itself eliminates 83% of incoming fire; in conjunction with agility and other defenses, it radically reduces the effectiveness of nuclear missiles. A small ship universe produces large numbers of small ships each of which must either independently spend for their own nuclear damper or accept having their weapons quickly scrubbed away by heavy missile fire. Similarly, a big ship requires a single computer; a large number of smaller ships means a large number of computers.
The power situation also creates a problem: the fixed power requirement of the nuclear damper means a larger percentage of the smaller ship must be devoted to power plant and fuel to serve the damper. It is very difficult for a smaller ship to manage defense, agility, and firepower all in one package. So, the cost of a 50,000-ton cruiser does not produce 10 5000-minidreadnoughts or 50 1000-ton attack ships of equivalent firepower; the cost of a 15,000-ton battlerider does not produce 15 1000-ton attack riders of equivalent firepower.
That being the case, an attacking fleet has to spend from a third to a half again more in budget to field equivalent firepower, which becomes relevant only when trying to field a force capable of penetrating the defenses of a heavily populated world - in other circumstances, the weaknesses of the opposing forces cancel each other out. In other words, a small-ship universe is one in which assault of a main world like Regina or Jewell is more costly and therefore less attractive.
Now, how unattractive is up to you. You control the politics in your own universe. If you want a universe in which the 6 billion residents of Jewel and their hundreds of thousands of troops and thousands of missile and bay-meson batteries can be overwhelmed by a couple thousand 5000-ton minidreadnoughts escorting thousands of transports, more power to you. If on the other hand you want to say the 8 billion souls of Cronor aren't willing to be taxed enough to support the thousands of minidreadnoughts and transports needed to accomplish the conquest of Jewell, then that's certainly a defensible view as well.
However, the OTU didn't give enough credit to planetary defense in the first place, so I'd be wary of taking that big-ship universe as an example from which to draw conclusions about a small-ship variant. Jewell could easily have afforded a couple dozen or more deep-meson sites to oppose Zhodani dreadnoughts and keep their transports at bay. Even Regina ought to be able to bring down a few big ships if they dared a planetary assault.
