Whilst I don't think its "UNBEARABLY BROKEN" spell. I feel like it gives significantly more options then another spell in the same tier for the same cost. If you don't know what I'm talking about I'm mentioning the Tome of Cold Dark's "Summon Snow Spirit" Spell which is both in the same tier and the same cost. The function of both spells are essentially the same except that in order to create a snow spirit from Summon Elemental, you require an ice tile. Otherwise you will create a different elemental of the same strength of a different element. The only real situation in which "summon snow spirit" is better then Summon elemental is if you SPECIFICALLY want a Snow spirit and there isn't a single snow tile on the map. Otherwise if two players at essentially the same point in the game were to pick one of these two spells. The geomancy player would have a significant advantage as they have essentially acquired a very reliable summon spell that includes 3 elementals INCLUDING the one learned from Cold dark's book. It feels weirdly redundant to give so many options, including the option from another vanilla book in the same tier, to a single spell. The outcome isnt even random, but is infinitely repeatable as long as you have a required terrain spot.
Essentially, I feel like cold dark's summon snow spirit spell would need a slight buff or at least cost less then the summon elementals spell, considering how focused it is on summoning a single type of elemental rather then giving you the diverse options of a multitude of already useful ones.
Basically, if you had your three random spells to research be one of these two. You would almost always want to pick the one that gives you way more options unless there's the odd situation where there's not a single snow tile in a safe location for you. Even more of a easy decision if you have artic adaptation and can summon snow spirits anyway with geomancy, but with the added benefit of creating anything else.