Therefore, they come in variety of sizes and shapes. Therefore, say, do 100 stars travelling together in space make a galaxy? How about 10 or 1000 stars? How about 3 merging galaxies - is it one galaxy or 2 or 3? How about a galaxy broken apart into many star clusters by a tidal force of passing by monster galaxy? So, how to define (in order to count) them anyway? By one definition there will be many more galaxies than by another.

But on the other hand, pattern of H clouds contracting into galaxies and into stars is governed by inverse square law of gravity, rate of space expansion and by Newtonial dynamics of motion, so the dynamics of galaxies formation/evolution can be modeled/predicted with reasonable accuracy (limited mainly by how detailed is the set of initial conditions you use).

So, in case of galaxies I do not think there is one grand principle from which you can calculate their distribution pattern.