A la Sensible Soccer (which ran far more leagues than any CM game you care to mention, on an A500)
Yes but Sensi did'nt really do much with them - just had them - CM4 actually simulates realistically all the leagues - you cannot compare the 2.
As you say (using the sensi method) you could have billions of leagues if you wanted too its what you do with them that counts.
I would rather less leagues but more detail and individuality of those that are there.