The amount of ship types has no affect on if the AI will build or not.
Theres some factors here
A)What are my current fighter, corvette, frigate, and capital demand?
B)What are my current counter fighter, corvette, frigate, and capital demand?(this is determined in part by scouting..you also have not defined a scout for the AI in CpuBuild which can affect this, it also needs to know there what ship is a scout besides classdef).
At least with your AI without my mods, the hw2.log is filled with stuff to do with subsystems, since the AI still has a demand for them but it has none to build..but at any rate, I should have fixed it locally soonish.