With Napoli and Inter Milan as two best candidates for Scudetto next season, it makes sense because they have best player resources in Serie A. It's only uncertain about Inter Milan performances as they lost Simone Inzaghi and assigned a very young and inexperienced coach Chivu to replace Inzaghi. If we talk about that with Inter Milan, we must mention similar issue at Juventus with Tudor.
It's surprising that AS Roma and Atalanta have very different odds by changes in their head coach positions, with Gasperini moved from Atalanta to Roma this summer. I truly think both AS Roma and AC Milan will not be able to win Scudetto in a new season.
Napoli remains a strong team next season, having been one of the most prominent in recruiting new players this season, leaving them with a strong chance of competing for the Scudetto. Inter Milan will start with a new coach as will Juventus. However, I don't consider Atalanta a worthy contender for the Scudetto next season due to the lack of quality in their players, despite their impressive performance last season.
Inter Milan and Juventus could pose a serious threat to Napoli, even though both have appointed new coaches. Their performances could improve due to the hope their new coaches bring. I agree with you about AS Roma and AC Milan, as these two teams don't have as good a chance as the other strong teams.