Wolves in the wild typically only live between 6 and 8 years. If these wolves are 10, then they are really decrepit old senior citizens at this point. And once they get habituated to killing livestock, they will not stop. They will just keep coming back time and time again, just as these wolves did.

Think of this as being more of an act of euthanasia. It is really showing kindness to them, to relieve them from the stress and misery of old age, and all of its pains and disabilities.   They have lived long and good lives, and eaten plenty of meat.   Let them move on to wolf heaven.  It is their proper time.