Harmony - Troop Symmetry

Yes, I agree with you guys, but this is much more situational than it was originally. You can’t rely on just one or two spells, and if they don’t appear or turn out to be useless, it reduces the variability of your build (discarding skills that become useless with this balance, even though they could be useful with the default settings).
A situational summon is better, honestly. With the current schools in Sylvan, there is still an opportunity to invest in summoning, such as a Dire Wolf, and not just that. And then, please, you can summon wasps or a phantom, which often appears in Elven cities. But this is already a conscious choice by the player, and not a narrowly specialized build imposed by the game.