The above is totally dependent on the specialists at the institution and their preference of candidates. There are residency programs (surgery or something else) that will basically only take applicants that went the traditional route (vet school, internship, +/- specialty internship). Some don't even want anyone that has done a specialty internship for the reason mentioned above.
As for a candidate being less amenable to learn good surgical and medical practices, it also totally depends on the individual. I've worked with multiple surgery residents that were in practice for years and came back for residency and are great surgeons. On the other hand, I've also seen and worked with many interns that are resistant to learning a better and correct way of doing certain things. Bottom line, if you are to be an intern or a resident, take the opportunity to learn from your various mentors and become a better doctor by combining the best they have to offer.