I have no doubt that Huck entered the race with the sole purpose of injuring Cruz and Walker, both with evangelical backgrounds.
True, especially Cruz IMO - the GOP e knows that Newt could taken that SC momentum into Florida and ended it for Mitt in 2012 - by staying on his SC message. He abandoned that message day one in Florida and attacked Mitt. They know Cruz can very well win SC, and that he won't be as foolish as Newt was in Florida. They know there's a path for Cruz to have this thing almost sewn up by Florida, or for it to be down to only Cruz and Walker by that point.
Of course, for Huckabee to foil Cruz and Walker, he'll have to do well in Iowa (he won't this time) and then really entangle the evangelicals in SC.
I think the GOP e could live with Walker, though he's not their first choice. They hate Cruz with a passion.
I think you give him to much credit, his plan is far more simple.
1. Accept campaign contributions
2. Use contributions to buy your new book
3. profit.