In human mercenary bands halflings have access to the full range of helmets, giving them access to defense 10 hats. Including access to the Lion Helm which is a faction specific hat for the reiklanders. In the Witch Hunter warband, Halflings only have access to the helmets which are available to both the witch hunters and the other mercenary bands. This means they don't have access to the defense 10 helmets of the human mercenaries, or the special cosmetic helmets of the witch hunters. I conclude that one of those things is a bug. Either they should get access to the full range of mercenary helms so that all halflings have access to the same gear. Or they should get access to the Witch Hunter only hats as they are part of the witch hunter warband. If my opinion on which way you should fix it is relevant, then: STOVE HATS!!!! otherwise a fix in either direction would be acceptable.