If one is farming or raising boars, one must construct roundpole fences. Keeps the deer from eating the crops. Keeps boars from wandering off.

Roundpole fences, however, provide little in the way of security from greydwarves, trolls, skeletons, draughr, wolves, and drakes which may come calling at one's base to beat out a viking's brains. Crops and boars quickly become collateral damage, especially if a viking is on one side of a pen or field and the gentlemen callers are on the other.

A viking could build walls and moats to protect his boar and crops. Mine is too lazy. Instead, he relies on location.

He puts his pens and fields far enough from his base to be outside raid range, that red circle appearing on the map during a raid. Mobs are pretty much single-minded: kill vikings. They don't wander across the countryside seeking out a viking's boar and crops.

If one stays in one's base and the red-tinted raid area throughout the raid, one's boar and crops will be untouched. Fight the mobs one can kill and dodge those one cannot until the raid timer runs out.

My viking also keeps his walled base fairly compact. He leaves plenty of room in the red circle to move around so that his structures don't take too much collateral damage from the mobs' near misses.

Should survival dictate leaving the raid's red circle, a prudent viking chooses a direction that does not lead to his fields and pens.

Yes, a viking must travel a couple of hundred meters to plant or harvest crops and to feed or slaughter boar. My viking would rather do that than worry about the safety of his boar and crops.