The rest of the characters chosen for Sm4sh imo need to be of the most requested/popular characters, or at least 90 %. Kawashima, Nintendog, Anna and Harry are not in that category, so if we're looking at it that way, none of them are that popular.
Are they impossible? No. Are they likely? Absolutely not. Especially when a roster has ALL of them. That isn't a risk. That's just being stupid. Pick ONE of them, and that's a risk.
Even then, they're all unlikely. Nintendog won't happen based on the fact that that's a lawsuit waiting to happen. Kawashima could, but is hardly requested and may not be eligible. Anna is essentially overshadowed by Chrom and Roy by a very long shot, and Harry is possible, but Virtual boy.