Well, Fynn won a 3 mos. contract on Days in a contest in Australia. I think the show sort of liked him, and since they were going to exit Daniel, I believe they kept him a bit longer. But who knows? The only other doctor they have is Kayla, since they chose not to put any other Hortons or Bradys into the medical field.
See, I think it would have been better if say...Lani came on as a doctor, rather than a cop, but then, they would not have had her interacting with Daddy, Roman, Rafe, Shawn, would they?
The thing with Belle & Shawn is......Shawn was the one working in a law office (Mickey's) while Belle was into fashion design. Then they went off on the high seas with their baby......and returned, under different writers with different careers, both really just beginning them.
But the writing has been really terrible for them, both had personality changes as well.