I think you overstate Carson and understate huckabee. Huckabee is an excellent campaigner and he won Iowa 8 years ago. He is likely to do well there again. I think his real stumbling potential is money.
What's interesting about Mike is he is not at all running a tea party/right wing fantasy campaign. He's running as a unique candidate when compared to every single other person in the primary.
I've said it before - he is really, really far from my beliefs, but I do think he is principled and I understand why people vote for him.
Carson, on the other hand, is the flavor of the month with no real shot at winning anything. He will have a good polling wave at some point and then fall off the map.