My interest in playing elemental plummets without the custom unit design. It's where they've hung their hats, at the expense of other things. It's what makes Elemental unique.
You may scoff, but balance in primarily single player games is overrated. I can't think of a single SP rpg or strategy game worth a damn that has ever been completely balanced out of the box. There were always some imbalanced units or strategies, and discovering them let you feel clever, which provided an appeal of its own. It was part of the character of the game. We may appreciate game balance, and decry the lack of it, but we don't fall in love with games because of it. At least I don't.
I'm certainly not saying that balance isn't important, shouldn't be striven for, and that FE in particular doesn't need a crap ton of work in this area. Faction differentiation, unit balance, the army system are all areas that need serious attention. But in my opinion, like we see in Crusader Kings 2, the best Strategy games are games that let us generate unique personal stories. Starcraft is an almost perfectly balanced game, with three completely different factions. But they aren't *my* factions.That game does not scratch the same itch that FE does.
I want to play the game that let's me attach a magic ring to a unit to give them a fire attack, but because of the financial situation in the kingdom, make them go without boots to recoup the cost, and name that brigade the "Firewalkers". Obviously, I also want there to be gameplay-enforced pros and cons to doing so. Even sandbox games need functioning rules. I want to be able to make *strategic* decisions about outfitting a troop with one less piece of equipment, because doing so will let me build it in 4 turns, instead of 5, which will have an impact in the current situation, and yet still have it be strong enough to deal with an incoming threat, which a dev-designed unit may not be. I want to be able to make *strategic* decisions about how to optimize the resources I have, for each given situation. But mostly, I want to be able to envision my own unit concepts, because there's a creative appeal to doing so,
The ability to fine tune your units for any given situation, and make them part of a story that *you* author has a distinct value all its own. Not for everyone, of course, but no game is for everyone. Not everyone cares about generating their own stories, and there are plenty of games that don't do that (and yet are still not perfectly balanced).
If you sanded off the parts that make elemental distinct, you end up with a poor man's HOMM. Not interested. I'm barely interested in HOMM, as I find the games too shallow to sustain repeat play. In my opinion, they have little choice but to make sure the unit design and story authoring elements function well, or there's really no reason for the game at all.