what I have heard(for what that may be worth) is it is harder to make smaller hatchets.
I own both and I would get the mini, it is a take everywhere size and very handy. and later if you want you could get a larger beater (cheaper) hatchet for the dirty work and not beat as upset if you ding it up. I know my local Ace has Collins hatchets and axes around 12 or 15 inches long for $20 or less, these would compare to the wildlife in size.
I own a Wettlings in wildlife size too. and I like it better than the GB wildlife, even though it needed sharpening when it came compared to how most GB show up freaky sharp, but it just fits my hand better. It is an old style Wetterlings, not a new GF Wett. model.
Pat
P.S. there are other hatchets coming out with a shorter handle now at 8 to 10 inches, but they are just not as refined as the mini GB once people get one, about all them comment on how it just seem to come to life in their hand and how useful it is.
Pat