"Holmes' relationship with Watson would no longer be that of mentor to mule, but a modern bromance; they would, moreover, be men who could look after themselves in a stoush."

What? Mentor to mule? I've always read the Holmes-Watson relationship as that of two men who respected the talents and qualities of the other. Those talents were complimentary, and sometimes at odds, but the synergy of their relationship is best defined by the modern term, "bromance", and far from the mentor-student relationship. Watson was always a man of action, unafraid of getting physical the situation required it. Holmes, while certainly more cerebral, could appreciate that brute force was sometimes more appropriate and acceptable.