my question is can a number be as many/much as another number...
precisely what I implied through alternate phrasing
The number of dogs is twice as many as the number of cats.
seems a little awkward. You are trying to say: The number is twice as many
I would prefer: The number is twice
(Note that here the subject is Number and not dogs)
However, if you use Dogs as subject, you may use "twice as many..."
Would like to have more opinions on this.