If Su Changkong's Giant Whale Skill and Turtle Breath Technique were both at Tier 6, then the Tier 6 Giant Whale Skill would easily crush the combat power of even a Tier 7 Turtle Breath Technique in battle.
Indeed, Martial Arts differ in strength, and a Peerless Sword Technique of the same realm will certainly defeat an ordinary Swordsmanship of the same realm.
"If the Giant Whale Skill reaches Tier 7, reflecting Profound Mastery... the increase in fighting strength would probably not be much less than that of a Tier 9 Turtle Breath Technique, and if it reaches Tier 8... it might even surpass a Tier 9 Turtle Breath Technique!"
Su Changkong thought to himself.
Lower-tier Martial Arts are simple and easier to practice, but they have a lower ceiling compared to higher-tier Martial Arts; mysterious and high-tier Martial Skills and Techniques demand greater talent, are harder to begin with, and even more challenging to master deeply, but their ceiling is much higher!