The helmet (+6 all) is an overpowered artifact (class: relic), and it is equivalent to three artifacts of the same class (relic), for example, the Sandals of the Saints (+2 all). There's no point in comparing it to sea relics, which have a value of 0 in skirmish maps without water and which also need to be removed somehow. And luck can often influence the outcome of the game; for example, one player in a low-level map might get the Sandals or Boots of Levitation, while another gets the helmet. Where is the fairness? This factor definitely needs to be minimized in some way, but not by creating conditions that only allow the use of this artifact, because that would disadvantage the player who gets it. I believe that it should be technically implemented so that it, and probably also the +5 all sword, do not appear on the map.
According to clause 5.18: It is possible to agree with an opponent before the game to play without logistics.