Wow ! What to add to the comprehensive description Allen is providing. He knows his work and I am sure he has seen what are the best and the worst.

I would modestly add that a good PH is capable to extirp the best from his even recalcitrant or desperate client. He can entice him in being of better mood ( when waking up, when lady luck is trolling elsewhere.....etc..), be enthralled with the getting of representative decent trophies far from a World record class....................and best he can coax him in stalking many many hours, many many miles, what usually the client wouldn’t do even for a goldmine.
My classement would be 1) bushcraftmanship 2) be obeyed and enjoyed by the hunting team (so as to get the best from them,)3) fast assess the game and fast make shoot.
Estimating a game and showing it require experience and talent.
The value of a good PH is to show the game and to depict precisely and quickly where it is. The one who know how makes shoot more valuable game than other equally good Phs.

Allan will you be kind enough to tell us how often the client was not able to see the game quickly enough to shoot it?