Adam,
your perception is probably spot on.
Tom,
my experience of fescue in an arid condition comes from central Europe and not GB which as you rightly say does not suffer from such a climate. I think that Adam has it spot on that most golfers look at the brown and thin (compared to bent) playing surfaces and think it is struggling.
My experience is that fescue handles daily high temperatures in excess of the 100F mark for weeks on end with no rainfall quite comfortably if the soil is free draining, playing surfaces correctly maintained and irrigation water delivered at a temperature closer to the ground temp than most irrigation systems do. HOC a little higher, roll as often as cut, don't feed and no midday watering. Yes, it has a colour closer to sand than green fields but still plays great.
Having said that if the other course has bent then it makes sense to use it on the new course unless you are looking for a contrast.
Jon