Simple question here...see, by now, if it isn't blindingly apparent that every sphere has attack grims, I don't know where you've been.
Falkow has eldritch hands, black storm (this one is actually rather dependable IMO), thunderheads, and tempest. Not exactly the greatest candidate for grim damage, but Falkow doesn't need it thanks to its return grims, which provide it massive utility in the large majority of matchups.
Lawtia: it's a bit more situational, with cards such as criminal edge, tears of blood, and pure terror. But generally, Lawtia grims used in the endgame have the ability to hit as hard as Gowen's, without the necessity of raising sphere too much. If you put in overdose on MD augment, that's 100 damage right there for 2 SP. However, you rarely see these grims because spending multiple SP to force 1 or 2 SP in revives just isn't efficient when you can instead skill up and learn to time death's embrace and bitter destiny, and say "**** you!" to your opponent when your 3 SP grim wipes out 5+ SP in one go.
Refess: the sphere that IMO goes stride for stride with Gowen on attack grims, and even one-ups it in quite a few cases where defense or undeads are involved. Hand of god, burning sun, judgment hammer, and magic bolt (with folrart mage support) round out its collection, and between those grims, you basically have the answer to just about anything you want to kill. Oh, and there's also hero's strike, which I have no idea why you'd want to use it, but okay. (Actually I can see FFS+salamander->toromea->hero's strike on an eskatia->fireball breath vs. EN)
Now onto Gowen: yeah, it's got a lot of low-level attack grims. Roar of anger. Brave Strike. Dragon breath. Dragon fire. Burning air. Fire snake whip. Boulder drop. River of fire. And then it has some mid-level attack grims. Fire arrow. Explosion of anger. Ball of flame. Rain of arrows. Fire tornado. Roar of the Flame Emperor. Yep, it's got a bunch of them. Problem being? They're all more or less variations on a theme--spend an inefficient amount of SP at the end of the game to wipe out final copies when LP is a more pressing issue than SP, since you have SP from dying units. Problem with that? There's only so many of these grims you can pack. Although they all have their situations in which they shine, there are only so many of them you can pack. A dragon breath, a couple of fire arrows, and maybe a ball of flame, and that's basically all of the grimspam (11 SP total) that a file outside of big red can really sustain.
Which brings us to the big issue--what the heck are Gowen's non-attack grims supposed to do? There are a handful I can think of:
Ignition, Fairy Dance, Magic Weapon, Song for a Hero, Reforestation, Miracle Fruit, Gravity Sphere, and maybe you can count Lawtia's punishment hole in there too.
Now, compare all of the above to:
Sweeping tidalwave, return, cyclone, wrath of the sea lord.
Exchange of souls, death's embrace, bitter destiny.
Solar cage, mirror of light, general's order, key to the holy realm.
The comparison in tech grims isn't even close. General's Orders makes any Gowen buff grim look absolutely silly by comparison, and Falkow and Lawtia's "this is a low SP game in which we have the advantage" simply invalidate a long laundry list of strategies that just might work if you had the SP to play them.
Oh, right...Gowen used to have one really decent tech grim, coupled with a certain SS that forced a low-SP environment ala Lawtia/Falkow. Yep, I'm talking about fruit + double RFA. Too bad that got nerfed to the point that you can't really use it too well against rushes, huh?
So, testers, when is Gowen going to get any decent tech grims?