Has anyone tested which provides better passive damage buff between Red-Haired Yaksha vs. Turtle Treasure spirits?

I've upgraded both spirits to level 4.

• Red-Haired Yaksha says it "Considerably increases Heavy Attack Damage.

• Turtle Treasure says it "Considerably increases Damage dealt by Heavy Attacks that cost 3 or 4 Focus Points."

I'm guessing Yaksha's buff is slightly less overall since it affects all Heavy Attacks, while Turtle's buff is slightly higher since it's restricted to Focus Point attacks?