If "
should" is the proposal? Well, in that case, let's pop on the somewhat long explanation, background if we may, on the situation in Iwa according to your post. I'm not going to regurgitate it here cause a summary might detract from your meaning.
The Tsuchikage of the time (don't kill me for spelling errors
) was doing a poor job at trying to maintain the defenses of the village by relaying it to a defender. For obvious reasons, with lack of information on Iwa defenses, the defenders had to fight with what they had, which apparently was not enough to stop Bocc in the end.
Creating defenses mostly, in this current age and time from my experience, primarily deters attackers to begin with, unless (forgive me if you're insulted) you happen to live in Sunagakure or Iwagakure. Kumo's village didn't even spawn in SL until the same time (appx) that Iwa's became very much accessible. It isn't Bocc's fault that the Kage was unable to properly perform the defense of his own village during the relaying of what defenses the village had to one of the key defenders.
Kumo, to be honest, almost spawned outta nowhere for me, since I hadn't expected it to grow so much. But so relative little is known about Iwagakure compared to even Kirigakure and Kumogakure. They had about the same amount of time as Kumo to get their crap together. In the end, the stone just didn't appeal to enough people to make it strong enough to repel Bocc.
In such an instance, the defenders themselves could have merely claimed the creation of defenses that apparently were not completely outlined on a wiki page prior to the start of the conflict, and thus got creative to counter the threat as a group. However, since the Kage and a council are the only ones, in a sense, who have that authority, they were left throwing stones at Tiger II tanks. As you can imagine, unless you hit it just right, you might as well try to make the rocks jammers for the tracks. (probably an exxageration on my part, but it makes the picture clear for those of you who get it)
Bottom line is, especially with the Iwa incident, anyone should have the authority, right even, to set up barriers to defend their village. The maintaining and keeping of the barrier then would be at the discretion of the parties and powers to be. Not every Kage or Council leader can be on conveniently when the attacks happen (sometimes coincidence: other times, I think not) and orchestrate defense activation or creation at the last second.