Clerics always filled the Witch-Hunter role just fine, I think.
If I were running a Colonial Era game, I'd probably reskin the Elf as a Native Shaman. Think "Last of the Mohican" fighting capabilities mixed with a dabbling in shamanic magic.
I'd reskin the Dwarf as a forgotten, Nordic Viking tribe recently emerged from the North. Long settled since the Norse expansions centuries prior. A "berserker" type, I guess.
And I'd reskin the Halfling as a Hunter/Ranger/Bushman.