Lacking routine responses only causes difficulty when encounters recur. [definitional]
To say that a people are not equipped to deal with strangers routinely is not to say that they are not equipped to deal with them at all or are equipped to do so only with great difficulty. As long as strangers appear infrequently, there is no need for routine handling and thus, the lack of a capacity for it poses no difficulty. One might even argue that killing the stranger, for example, not an uncommon response in times past, was a rather efficient method of "dealing with" unwanted visitors. It is only when strangers appear routinely among a people unarmed with routine handling procedures that we can begin to talk meaningfully about "difficulties."
DEFINE: Defines when the absence of a capacity to handle strangers becomes a genuine problem — only under conditions of routine, frequent encounters.
Lyn H. Lofland, World of Strangers_ Order a…, loc. 1052