Wound channel size, that is “margin of error” in shot placement, is determined by two things only- projectile design and impact velocity. Ft-lbs of energy is not a wounding mechanism and tells you absolutely nothing about what that bullet will do in tissue. “Killing power” is the combination of bullet placement and the specific projectile and impact velocity. There is not nearly the difference in sounding capability between calibers/cartridges that people believe.
For instance, your stated 300WSM with 180gr Accubond at 3,000fps MV versus a 7mm-08 with 162gr ELD-M at 2,650fps MV at 600 yards has almost exactly the same impact velocity, the 300WSM has more wind drift and greatly more recoil. The wound channel from the 162gr ELD-M will be measurably larger than the 180gr Accubond at that range.
Now you could change the bullet and get a better BC to match the wind drift and match or exceed the wound channel of the 7mm 162gr ELD-M, but in doing so you are going to increase recoil even more. Also, the barrel life of the 300WSM is around half or less of the 7mm-08.