I could easily add it up too my questions is what are the target DCs for EN (we rarely do hard and never elite) and you also assumed non-int based...int based is 18 Int + all sta-ups so your short by about 4-5 DCs.
You should have no problem with EN DC's. You will probably do fine in most EH too. Good assassins know their foes, you don't rly need to be able to assassinate every mob, you can always focus your attacks on low fort mobs.