I had an idea after watching this video.
There are Magogs; we could create an improved Magog, like in Heroes 3, with two blades (rank 10).
Added 16 minutes later
I checked... this flame attack doesn't work for ranged attacks at all, not even in melee, not even in a single shot.
Yesterday, I tested a build for Inferno using Magogs... and as planned, they shoot, deal area-of-effect damage, and destroy their own units... This leads to a certain kind of chaos, which is quite amusing, and I haven't really encountered this kind of gameplay in Heroes 5.
Although, no, I did encounter it with the Balbes – Free Cyclops. But even there, it's a different concept. Here, the damage to everyone is predictable (while with the Balbes, it's a matter of luck). You can shoot while the enemy is far away, but if they get close to your formation, you can't shoot anymore because you'll destroy your own units!
It turned out to be very interesting and unique in its own way.

In general, this unit didn't become overpowered, and for the late or endgame, Leapers will be preferable.
But, of course, Magogs will be used at the start.
Let's add that if the stars align (archer set, claw, expert divine power, etc.), then Magogs can deal excellent damage to enemies... but, of course, everything has to come together :3