Is a different meditation better for my colleague's breath counting obsession?

My co-worker began practicing mindfulness to manage work-related stress, but now he is compulsively counting his inhalations and feels irritated when he becomes distracted. He is under pressure to have the count right. His friend is concerned that this attention to perfection is turning into an anxiety disorder and exacerbating his general stress. His name is Ajay, DOB is 15th December 1994. Should he change to mantra-based practice in order to remove emphasis on his breath?