The rankings that I used are from Capcom's official sales figure for each of their franchises, so:
- Resident Evil (98 million copies)
- Monster Hunter (63 million copies)
- Street Fighter (44 million copies)
- Mega Man (36 million copies)
- Devil May Cry (22 million copies)
One relatively common argument I've heard for Dante's inclusion is he's the main character of the largest Capcom series not to have content in Smash, so he's therefore the next most likely character to get into Smash. However, this doesn't really correlate with how Capcom has licensed characters to Smash before. Rather than starting with Resident Evil and working down for each franchise, they instead started at Mega Man and worked up. Likewise, Street Fighter and Mega Man got the greatest amount of content (characters, remixes, a stage, assist trophies, etc.) while Monster Hunter and especially Resident Evil got comparatively little, so it's also not a case of the largest getting the most amount of content either.
Ultimately, why I rank Travis higher than Dante is due to his Nintendo connections. I definitely agree with you that, by most other objective criteria, Dante outedges Travis. However, we've seen in both DLC cycles a common trend for one of the characters, a smaller third party who got in (mostly) due to their strong Nintendo connections.
was this character in Smash 4 and
was this character in Ultimate. While Travis hasn't had Nintendo directly involved in the development and publishing of his games like the above characters, every entry in his series began as a Nintendo exclusive and Nintendo has been pushing the upcoming No More Heroes III pretty hard. Through this niche, Travis has a much more direct path to the battle than Dante, who's stuck competing with a much larger pool of applicants.
While it doesn't harm Dante in a vacuum, it harms him in the sense that he lacks certain attractive qualities that substantially set him apart from his peers and thusly puts him into a greater pool for competition. For example, if Capcom did have a pattern of choosing their largest franchises to be the next Smash rep, then that automatically elevates him above the likes of Phoenix Wright and Amaterasu. However, that pattern doesn't exist, therefore Dante can't leverage his series' size into an increased probability for his chance at joining Smash Bros. He's still entirely possible, but he's not a guarantee like many assume him to be.