Frankly I don't think any punishment that Goodell institutes is going to be too strict here. You need to hit Gregg Williams and Sean Payton hard here. Both knew about this and did nothing to stop it. I don't know if you can actually go after the players here, because its hard to know who was really involved here, but I'm sure the investigation can provide some information. Fining Benson, Loomis and taking away draft picks are fine. At least a #1 pick should be taken from 2013 and frankly take away their #2 pick from this year's draft.
The NFL is already seen as a violent league. There are ex-players suing the league because they didn't do enough to protect the health of the players. Goodell has to lay the hammer on New Orleans and make sure this doesn't happen ever again. So as I said, I don't think there is a punishment he can lay on the Saints that is going to be too strict here.