i had to accept that neither player was ever going to do it for us
You've clearly forgotten the second half of 2008-9, then, because Cotterill was a major factor in our rise to third place.
I think my favourite was Newcastle when he switched the legendary wing man Jordan Stewart to the right wing rather than bring Cotts into the action. Spent 15 minutes like this before Cotts came on and created three reasonable scoring opportunities in the quarter of an hour he was allowed.
All of which were wasted by Henderson.
As an aside, I am always amazed by the number of people who claim that Cotterill cannot cross a ball despite there being acres of TV footage to the contrary. Why, that very evening, Seth Bennett claimed that Cotterill hadn't created anything after he came on and challenged a Football Heaven caller to name one chance he'd created. When the guy named two, Bennett said "you're just clutching at straws"!
Cotterill has his flaws, sure, but to say he can't cross a ball or didn't contribute that season after being restored to the side is just wilful blindness.