Drice5, welcome to SMF! Glad you are here and asking questions.
You can use a rub with sugar on a brisket with absolutely no problems. The real issue is whether sugar and beef go together. Personally, especially with brisket, I'm a SPOG guy (Salt, Pepper, Onion Power, Garlic Powder). I save the sugar rubs for pork and sometimes chicken.
If you like the taste of the rub with sugar I'm sure you love the brisket. Smoke away!