Yes: they have more players and can rest ThuLa, for example, with substitutes that no other competitor has in their squad. Good rotation, the kind that allows the team to maintain its level, can bring important results. Milan and Napoli don't have the same level of substitutes, although I'd put the Azzurri behind Inter once they've recovered all their injuries. The other teams will be fighting for a Champions League spot.
There is a lot on the line in the first Milan derby of the season, but that in itself is something that should be celebrated. La Gazzetta dello Sport (seen below) speaks about the essence of tonight's derby with a simple phrase: whoever wins takes the city. Inter can extend their lead to five points over Milan, the Rossoneri can overtake them by a point. But there's much more at stake than the Navigli.