Well... this sort of goes for half of your Pokemon, actually... Dragonite, Sceptile and Typhlosion... pay attention to the primary attack stat of a Pokemon. ATK and Sp. Atk. are two different things. The three I mentioned all have at least one move in their neg. stat.
As for Typhlosion... It is just built ugly when compared to better fire types. I notice that you have no Fighting type Pokemon... perhaps a Blaziken would do well for you. If you insist on Typhlosion, though, I'd replace Thunder Punch with Sunny Day and Focus Blast with Extrasensory. Then drop the Choice Specs and use Wise Glasses. Flamethrower would be the go to STAB move, for sure.
Blastoise should be in an Assault Vest, as it has poor HP but can become a very key Tank. Scald>Surf for competitive battling because it has a decent chance of burning, which is a boon against Special Tank Blastoise checks.
Your Sceptile is Adamant, so stick with Physical Attacks or you are going to have a bad time. If you pop a Gem on it (Flying is good) and give it Acrobatics, you benefit from a speed boost, a HUGE base power Acrobatics at 165 and coverage against Grass and Bug Types as well as Fighting Types. this will help greatly against the most common Fire Types in the competitive scene (which are Dual Fire/Fighting). I would say the best moveset for a physical Sceptile utilizes Drain Punch, Sword Dance, Leaf Blade and Acrobatics (if you use the gem strategy) or Earthquake if you do not.
Jolly on Tyranitar is weird, as it will hardly ever outspeed anyone, even with maximum Speed investment. Adamant might do better, or a Defensive/Sp.Defensive nature. Nice Movepool, though.
Dragonite... oh, Dragonite. I don't think much can be done here.
Aggron is fine. Might want Iron Head.
On a Final note... you claim this is for Heart Gold, but you list some inconsistencies with abilities. This made it hard to set you up.
Your Dragonite can not exist.
Your Sceptile can not exist.
