Garchomp is Stronger because he has higher speed, Health, and defense and Not just attack. Salamance has 3 weaknesses including a 4x to Ice and has 6 not very effective types against it. Salamance is Dragon/Flying. Garchomp Has 2 weaknesses including a 4x to ice too and he has 4 not very effective types. Garchomp is Drragon/Ground. Here are my reccomended moves:
Salamance: Attack: Dragon Claw, Iron Tail, Earthquake, Fly, Crunch, Steel Wing, Zen Headbutt, Brick Break, Stone Edge, Dragon Claw
Special Attack: Flamethrower, Fire Blast, Dragon Pulse
Garchomp: Attack: Earthquake, Dig, Dragon Claw, Dragon Rush, Crunch, Stone Edge, Shadow Claw, Brick break, Poison Jab
Special Attack: Fire Blast, Flamethower, Dragon Pulse
Aggron!!!!!!!!!!!!!!!!!!! Though he has a lower total base stat by 70, Here is why he is better. For 1, He Has HUGE defnse and excellent attack. Also, Listen to this: Aggron has 3 weaknesses with a 4x to Ground and Fighting BUT 10 types are not very effective!!!!!!! Tyranitar has 6 weaknesses including a 4x to fighting! Only 7 types are not very effective. Plus, Aggron learns Slightly better attacks. Here are my Reccomended moves for them:
Tyranitar: Attack: Crunch, Earthquake, Stone Edge, Dragon Claw, Iron Tail, Brick Break, Shadow Claw
Special Attack: Thunder, Thunderbolt, Fire Blast, Flamethrower, Dragon Pulse
Aggron: Attack: Iron Head, Iron Tail, Strength, Double Edge(If he has Rock Head), Stone Edge, Earthquake
Special Attack: Fire Blast, Flamethrower, SolarBaem, Ice Beam, Blizzard, Thunderbolt, Thunder