Bookmakers evaluate the chances of teams as follows:
2.90 - 3.50 - 2.38
I think it's fair that Napoli is the favorite (how could it be otherwise with such a phenomenal scoring game), but 2.9 for a Roma win looks tempting. It seems to me that Roma should win more often in such games than 35%. There are no guarantees, but in terms of distance, I think it's profitable to bet on Roma.
With odds like that I assume there is no favourite, and betting on any team will still give us a good advantage because the odds are almost the same. But for me considering the odds like that, then I will still bet on the team that is in their best form so far because they are unbeaten. Because to be honest Napoli in my view is a team that continues to improve from season to season even though they are, they are rarely in the title contenders as it will be easy to shake when the end of the season approaches. But because this is still part of the start of the season and Napoli will certainly try to maintain their good trend, therefore I really believe Napoli will still be able to win in this match.
Maybe I'm biased, but my opinion is "pressed" by the status of Mourinho, who is the killer of favorites. Roma has two defeats this season and both are not from weak teams, a victory over Inter and a draw with Juventus. Napoli's performance is incomparably better, but in Serie A they have only one "big" match (and victory) with Milan. All in all I see no reason why odds of 2.9 are bad.
Don't know why you seem tempted by the higher odds for Roma compared to Napoli. KTCampions, Napoli are a consistent team so far and it is difficult for me to justify that they will lose to Roma who have started well in recent match. Napoli are unbeaten in their last 10 matches in Serie A and I think that good trend will be maintained by Napoli in this match.
It may be true that something can change in a match due to chance, but Napoli are a team with a higher goal-productivity than any other team in Serie A at the moment. I think Napoli won this match, but Roma are a team that has improved now. 7 wins in 10 matches and only lost 2 and the rest were draws are good statistics from Mourinho's team. Interesting to look forward to.
I agree that Napoli are the favourites, but the question is how much they are "stronger on paper = the odds given by the bookmakers". As I wrote above, I don't see any reason to consider Napoli so strong that 2.9 odds on Roma would be unfavorable.