Actually, you have this slightly wrong, or were mis-informed about 5USC and 5 CFR.
First all applicants are reviewed to see if they make minimum eligibility by an HR Staffing Specialist. During this phase Veteran status is also determined.
Then, based upon the qualification standard, the same (usually anyway for consistency) HR Specialist will review those eligible applicants to determine the numerical order. [Agencies do this different, some will use the score as is without modification, other will not even use the score and provide what is called an unranked list, some will modify the score based upon the resume, just depends on the Agency].
After this is done, then the same HR Specialist (consistency) will construct a Certificate of Eligibles. 10% or more disabled Veterans will automatically go to the top of the list, end of statement (check 5 USC and 5 CFR), 10 point and 5 point Veterans will have the points added to their score. So now you have a Certificate, that lists the 10% or more disabled Veterans at the top, then everyone else by score order with augmented Vet points added.
This Certificate of Eligibles is then sent to the hiring Managers to interview and select the best candidate(s). Traditionally, if you have more than 4 or 5 Vets on the list, you don't even send the "others" over on the Certificate, since the odds of being able to get a "bypass" on all of them is astronomical. And, yes HR Specialist are very cautious during this phase. Not providing a Veteran the preference they deserve (or more appropriately, have earned) is a career ender, maybe an employment ender. Surprisingly, I have yet to have a total washout on a certificate with Veterans. There has always seemed to be an imminently qualified applicant in the Veterans group. Further, and many managers view it this way, Veterans do bring a special confidence and experience level to the job, often with new ideas that work.
There are a coupled of twists, like with category ranking and rating, but the 10% or more disabled Vets still go to the top of the top category, and all they have to do is make basic eligibility and qualification standards. As a twist, under the VA's Title 38 systems, the HR Specialist are restricted from making anything but basic eligibility/minimum qualifications standards determinations. With the pure Title 38 fields, this is no problem, because Vet Preference is used as a tie breaker. With the Hybrid title 38, and traditional Veterans Preference, well Vets must go to the top of the list because it is an unranked list.
Often, I ask why even bother to announce a position to all US Citizens, when all it takes if a couple of Veterans to block the list and you can't get to non-status candidates anyway. Just go ahead and announce it to all Status Candidates, where Veterans Preference allows Vets to apply but nothing special after that, and the manager can choose anyone from the list of status candidates provided. I have also had very good luck with this approach. And you get very seasoned/experienced employees this way also (that also bring new ideas to the table).