The Frankenstein Fleet

Kitbashes. Some love them, some hate them. But it is undeniable that they exist in the Star Trek universe.

So the question becomes, what is the reason for them to exist?

How are they (re)constructed given the different sized parts and connection points for conduits and turbolift shafts?

My Theory

Kitbashes come from sections of destroyed or damaged ships left over from previous wars, exploration missions, etc. The kitbashes encountered during TNG (most notably BoBW) were most likely remnants from the Cardassian and Tzenkethi Wars stored at junkyards like Qualor II for safe keeping until they might be needed.

That need arose after the encounter with the Borg at System J-25. Starfleet needed extra ships to defend the core world fast. Commander Shelby was put in charge of developing the fleet and weapons to stop the Borg. Her plan was two-fold, construct cheap and fast to build kitbashed ships for defense in the near term, while simultaneously developing long term advanced research projects like the Defiant, Quantum Torpedoes, Ablative Armor, the Prometheus Class, etc.

Later, during the Dominion War, we see more kitbashes, most likely left over from the two encounters with the Borg and pressed in service in order to bolster the fleets numbers in preperation for the coming war.

So, the question then becomes, how are these monstrosities actually built? They have parts of varying sizes and levels of technology. Connecting the various conduits and turbolift shafts, not to mention different sized Jefferies tubes and decks must be incredibly difficult.

Welding the parts together wouldn't do it, because you would have two or three distinct sections not actually connected to eachother.

Reconfiguring the internal sections of the ship manually would be extremely time consuming and costly in manpower and rescources and thus would negate the advantage of putting the ships into fleet rotation in the first place.

I think there must be a rapid way of reconfiguring the ships internal structure. Possible methods:
I believe all of these ships most likely have very small crews and are probably highly automated. They are merely stopgap measures to bolster the fleet in time of war or crisis, an not meant to stay in service afterwards.

In addition, I only direct this at some of the more outlandish kitbashes, the ones that can actually pass themselves off as a real ship built that way from the outset, like the New Orleans, Niagara, Centaur, etc. should remain exactly that, purpose built ships meant for long service lives.

I realize this does not answer the question of how a Peregrine Class fighter can become the engineering hull of an Intrepid Class saucer, but we will just have to assume that that it just looks like a Peregrine Class and was actually some larger vessel instead.

(Theory by Bond, James Bond)