Yes, yes, it's all about how knockback works, but melee knockback has a different price you pay for hits, different way how you play in order to apply it etc. I think this whole mess started with the devs trying to make an elegant solution to a fringe half-dragon issue (possibly magma mines) with HUGE concequences which weren't spotted in time because noone could get through the Pissorf tooltip well enough to make the right conclusions. Wouldn't be surprised if it was exactly that, because people were doing stuff with Orc Wizards but noone really thought it did anything if you weren't one and most people thought it was just an Orc Wizard thing (and were even doing it wrong).
And I've meant to reply to your fighter analysis, I liked it, and have you tried Warrior Pact on those Halfling Fighters? Looks like something to tack onto him just because he'd be munching popcorn (and spellcasting something down with a fighter is not an "any character" thing, fighters are kick ass spellcasters, this one is just more hybridy and takes less development for his physical side). Also do try a full Drac dwarf fighter, that's a scary thing (lifesteal gives double values against lower level monsters, and a dwarf becomes a monster with levels, making tha drac dwarf fighter scary s**t).
What I meant by reliable alternative to fireball is that it's reliable as a glyph to use when something is meant to deter firebal use (resistances, retaliation, blinking), while also being a reliable glyph to use when something is meant to deter physical attack use. So it's something you use when physical attacks fail you, when magical attacks fail you - and it even works against stuff that's supposed to be resistant to both. That makes it the default way of dealing with ANYTHING, and it's not priced or powered like it was supposed to be that, at any rate. Because IT would then be the 6 mana costing universal glyph and fireball would be an agresively costed "extra moving parts" specialist glyph with narrower application and skill requirements to incentive it's use over the more generally aplicable Pissorf (which also doubles as an exploration tool, making it even more handy). Or something, but that's just a thought because I've had little problems using Pissorf at 5 mana. There's plenty of other conclusions to be drawn from that, too. Nothing in this game is a counter to it's own counters, it'd be difficult to praise it for it's balance if anything was, and a lot of the learning/difficulty curve wouldn't really work if you didn't have to mix it up occasionally. And this thing is, currently, a counter to it's own counters.