You've missed his point. Quoting whisplike progression stats will not save you here. Rest assured, the mages here on these boards that you have just joined are far, far more progressed than you are. But that is beside the point, since you still missed his main one.
This part of yours is fundamentally wrong. That is what Stache is saying and I agree with him.
You can maximize DPS on priority targets while maximizing AoE, that is the point. Using Frost Bomb in this case is mathematically and realistically, wrong.
Now sure, in normal modes this does not matter much, but then again, not much does at that level. In normal modes, you can use pretty much whatever you wish.
And that is precisely where your argument breaks even further, with the simple fact that in normal modes, no matter which "bomb strategy" you wish to use, Horridon will die.
To that effect, as a DPS, your goal is to maximize DPS, which, in this case, will in fact be NT spam.. since the boss and priority targets will die anyway.
Now you can come back and say "sure.. but normal modes still count!", and you are entitled to your opinion for sure.
I think they don't really count, at least for the level of discussion we are having. If you are having trouble with Horridon normal modes, then I would hazard a guess that the numerical % theoretical differences between the bombs, heck, even the specs, is not what is holding you back.
Wrong.
You have done the fight on normal with your mage and heroic with your DK. Don't try to BS your way into thinking that "cross toon experience" works. It especially doesn't in this case since we are talking about core DPS mechanisms of a fight. You cannot say "I know how to mage in H Horridon" unless you have actually done it.
We don't accept that kind of BS here, you're new, so learn it.
The strategy with more DPS usually wins. WoW raiding isn't exactly rocket science. If you have to pick between two strategies that accomplish the exact same thing, with one of them also doing more DPS, then you pick the one that does more DPS.
I don't need to prove that. Its common 'effing sense.
After reading your thoughts, I think it most certainly is extremely trivial.
You are creating complications and postulating scenarios that do not actually exist.
Be warned, this type of thinking is a direct product of the "I dont need to actually do it I can just hypothesize experience" mentality, one that many people in this game (the mage MvP included) suffer from. It is also the mentality mages as a community have fought against since the beggining of MoP when trying to get people to understand issues, e.g. the level 90 talents.
Many people across the gamespace come out with "yea... I haven't played with the level 90 talents, but they look good on paper so you mages must be bullsh!tting when you complain".
Fun fact: You cannot "experience" something hypothetically. By its very nature, you must experience it to actually state that you have, or know what it means to experience it when others who have experienced it talk about it.