It's not a bad thing to make the best of it, no, but if you are sacrificing HPR, MR, and Intelligence, then I would say that could negatively affect your pet. Mana Regeneration (the whole formula, not just the MR stat) is one of the most important things for a pet. No matter the mana pool, a pet will zero out its mana eventually and then it is relying on mana regeneration to keep up with special abilities.
Dragon Breath can hit for a decent amount, but the unfortunate part of Dragon Breath is that it stops all attacks while casting, losing 2-3 swings in the process.
Dragon Breath formula is ((Hit Points / 5), which is then reduced by resists. This damage is capped at 200 damage pre-resists as well. At 750 health you would be doing 150 damage per Dragon Breath against a 0 resist target. Take a mid-spawn Navrey at 50% fire resist, you are down to 75 damage per Dragon Breath. Discorded to 22% fire, you would be back up to 117 per Dragon Breath.
With 700 Str, GM only Tactics/Anatomy, a pet will be hitting for 105-144 on 0 resist (82-112 on 22% resists). An Armor Ignore will hit for ~95-130. So it's pretty comparable to Dragon Breath, but you will be missing 2-3 of these attacks while your pet is casting dragon breath.
It's true you can't remove Dragon Breath, and I understand wanting to beef it up for when it does cast, but you really want to maintain as much mana regeneration as possible to allow your pet to spam as many other abilities as it can. If you want more hits on your pet for Dragon Breath and you don't plan on fully scrolling it out, you could pull from there (assuming you don't save points for possible 120's later), but personally I wouldn't pull from MR or HPR just for Dragon Breath.
To each their own though, everyone's play style is different.
Just from having plenty of time to watch it, It hits at a pretty fast rate, and the bigger loss of damage is when the fire steed casts a holy light for a whopping low 20's damage.
For dragon breath, the other consideration is it gives you a ranged attack. Not that this feature is a high value consideration.
If we're going to ding the fire steed, I would also include that it's only 80% fire damage so it's giving something away with the remaining 20% Physical as well, when the Chiv spells don't align. In practical use, I'm not seeing this bother me enough to make me seek a replacement choice.
This is a non scrolled pet, and it's goal was to test to see if Feint was noticable and worth the high budget cost. So it is (not it's real name), Prototype #3 after the AI,Mortal Strike/Chiv and the AI/Chiv firesteeds. Just part of the process of vetting theories, and near, but not quite ready for "production" with a final build.
I think it's a successful experiment, but it is costly out of it's training points budget, for both Feint and the High HP to facilitate a higher damage dragon breath. I might redo one again, with what I've learned so far, but before that, I would use it more extensively to see how it does as a general purpose pet. Also, it's still skill gaining on it's Chiv, so it's not fully representative of the 100% finished potential. If there is points, and if it seems like a good more general purpose pet, I think it might be a good prospect for 110 level scrolls. You've already got the prospect of "free" 108 resist, so with a Wrestle, Tactics, Anat, Parry you'd have a better than GM pet that was more attainable than all 120's. Not endorsing it, because, as I mentioned I haven't seen it work as a general purpose pet.
Dropping to 300 int from 370 didn't seem like a fail. It seemed like a fair thing to consider, to shave points. In the game, it still has a "good" rate of casting.
The other area I shaved points on was not giving it a big initial mana pool. I only dumped whatever I couldn't use that was let over into mana. My thought process on that was that it's not a magery pet and I couldn't think of a "mana dump" that a Chiv pet could win with, for anything that it couldn't already beat.
The "on paper" calculations are helpful though, so thanks for posting them. It's also good for explaining the pet AI's inner workings. A good Navery build doesn't mean it's going to be good as a general purpose pet, but I think Navery is a good test bed with its Magery/Poisoning and long fight time. Just to report in my findings, With Discord in effect, I'm seeing the Navery's in the low 30's for Fire Resist. The Discord being on the tamer, not on the pet.