Saut erreur, le seul cas où tu peux toucher une unité hors LOS, c'est quand tu touches toutes les unités en LOS, mais au moins une. Donc non, s'il n'y a que des unités hors LOS dans l'hex, tu ne peux rien toucher.
Seulement avec un mortier
C9.3. Spotters. A mortar is the only on-board weapon which may be fired against a target which is not in its LOS.
A7.4 TARGET DETERMINATION: Except during Defensive First Fire (8.1), all the Personnel-units/unarmored-vehicles/Vulnerable-PRC in the same Location are considered targets of fire that does not have to specify a particular target, with the outcome of such fire affecting all those enemy (or Melee) units in the target Location (except those to which the LOF is blocked, such as being entrenched behind a wall [B9.21], Area Target Type [C3.33], or non-Crest units in a Depression [B20.92]).
C3.33 AREA TARGET TYPE: ...All (including friendly) non-Aerial units in the target hex can be hit (even by WP), except for those immune as per 3.4 [EXC: a mortar also hits all target-hex units that are out of its firer's (Spotter's, if one is being used; 9.3) LOS if that shot hit the non-hidden enemy target that currently was the hardest for it to hit (i.e., that received the highest net TH DRM for that shot)].