No it doesnt. I have enough coaching experience to know not to teach people the waiters tray serve! And you either didnt understand what I wrote or dont understand how grips work. Its not just the index finger extending. Its the whole hand spreading out with a pistol grip. What you are missing is that that spreading of the fingers moves the heel pad. Any talk of an index knuckle location and the difference between hammer and pistol implies a heelpad position. Thats why good coaches focus on the index knuckle and NOT the heelpad. Here is a great vid that says just that at around 1:20 or so:
Sure especially if they want a one handed bh and I think they can hit with the same grip as their fh. And its not just me. Refering to the bh grip by way of the fh grip is actually a PRO tip for finding the eastern and sw bh grips on this site:
http://www.tennisnation.com/lessons-classes/ultimate-tennis-grip-system-guide/
Its best at this point not to critize posters coaching experience since yours is sketchy on the basics.