HR has adopted some draconian policies when it comes to dealing with layoffs. By this i mean the 'sudden death' methodology where the person is told, given a package, then walked out the door, only to return after hours to clean out their desk. They also don't allow the line managers to deliver the message, but have directors doing it... This, of course, leaves the line managers to repair the damage to morale and productivity.
Everything i've read says that this is the least effective way yet it seems rampant. I understand professional subordination to your boss but does that also apply to HR? I hate knowing there is a better, more effective way, yet feeling muzzled by my ethical duty to subordinate.
Have you spoken to HR and asked them if you can do it a different way? One of the worst jobs you'll ever have is to let someone go for any reason. I'm sure HR doesn't like doing this any more than anyone else. They might be thrilled to have someone else do the deed in their stead.
The above having been said, you must follow corporate directives. Work behind the scenes to make changes, but keep your opinions about "better ways" to yourself. If HR tells you the policy is immutable, then you have to "take the company line" and do your best with the situation you are in. This means not saying things against it, or otherwise trying to subvert the process.