You are absolutely right – as I said, Berserk is an area-of-effect spell, and all its mechanics work like other area-of-effect spells. If you place Fire Elementals on the left and cast Inferno instead of Berserk, it will look exactly the same.
Messages pop up immediately after selecting the spell in the spellbook in 4 cases: about cursed land, about the Cloak of Rejection, and about the Red Sphere (unique messages in each case), as well as "The spell will not affect anyone!" if it really doesn't affect anyone (taking into account artifacts, creature affiliation, etc.) and is not one of the first three cases (but there is a bug here – if there is only one target for the sacrifice and it can be both sacrificed and resurrected, there will be no message, but it will simply not be possible to choose a second target for the sacrifice). Another message may appear when casting Clone if there is no space for it, while mana and casting are still spent, but this is very rare.
It seems that these aspects are quite clear; where else should we look?