I have owned waterproof Merrell boots and they did not breathe well at all. I have not owned their Gore-Tex models. The Moab Ventilator is a good light hiking boot that I have used for years, but I'm not sure that anything Merrell makes would be a first choice for hunting.
I have used the Moab 2 for the past two years. They have been fine for me but my feet don't require a lot. They were pretty waterproof for the first year but have been lacking since. I have had to treat them with Nikwax 3 or 4 times in the past year. The boots have held up well other than that and I am planning to get one more year out of them before purchasing something else. I doubt the water resistance would be a large issue for you in AZ but I cannot speak to how well the soles will hold up in rocky terrain since I hunt the timber of northwest MT. IMO they are probably one of the best boots in their price range.
If you have very strong ankles the Moab boots can be used for just about anything, but they have less support than most boots even in the light hiking category. The all leather upper of the Prime version might help a little bit with that, but I wouldn't count on it. If you try them, please post your experience. I use heavy boots (Lowa Baffins) when I'm required to for my forestry work, but almost all of the time I wear them I wish I was using the Merrells.
They are not a high-end boot, and with daily wear have a life expectancy of probably about a year. Mine are two years old, but they look really bad, the outsole is nearly flat, and I'm probably damaging my feet by continuing to wear them.