With Natives roaming around the map, it is near impossible to get a treasure that your scout discovers home without it being captured by a Native. Wild Animals would only add to this problem if it is left as it is. If a man is carrying 1000 gold back home in a chest, it seems a bit silly that he would give it up without a fight. I suggest giving the treasure unit a weapon, and a strength of one, promising some sort of defence in the wild.