I wound wait until you get sides. No need to pile on meds unnecessarily. If sides happen, you won't get irreversible gyno overnight. Even though it takes a few weeks for low dose Aromasin to turn things around, you've got plenty of time once you start feeling nipple sensitivity.
Then in the future you can just start it right away if you're doing the same cycle and know sides are coming.
Like I said, Aromasin seems to be the best AI "on paper", but because of the way it works, it's critical to start low first, and only titrate up a little after a couple of weeks if symptoms don't resolve. Low and slow, and it's a good way to deal with E2 without the sides other, older AIs induce.