I have a pet whose maximum "level" is 42, and the number in parentheses is only 12. I have 100% on all of his attributes, 100% on power, and am 800/1000 to becoming Epic.
You don't really. The large number in the (##) is really the total of all the 'dots' in the gained abilities areas. As you gain these abilities, they will add to the second number, which is the total earned to date. As you only get 4 from each column, the number will never be anywhere near as large.
From what I have seen, Epic numbers above 20 are very rare. 24 would indicate a score of 3 in each of the 8 earned abilities.
increase your pet to teen adult ancient and epic the pet wont have a perfect 42 out of 42 a pet has 10 talents but it can only manifest 4 thats how the pedigree system works. i have an ice hound with an pedigree of 61 only manifested 23 your pet cant learn all talents