It is the exact same? And this pedestal you’re trying to put them on is fine if you wanna discuss importance, but that doesn’t translate to a power level???
		
		
	 
 Why will somebody weak will be included in a combo attack against the strongest being in an important panel.
Shiki, Gaban, Ray etc can replaced rookie Kaido and Mom logicall as they stronger? And could dish out stronger attack vs Imu? True.
But why does Oda decides weak rookie Kaido + Bigmom included in a combo attack of PK lvl characters against Imu? 
He did so, because it look epic in his minds if 3 future Yonko + 3 people that define that era (Xebec Garp Roger) fight against Imu....while every other legendary pirates who were in the same island gets sidelined doing minor things. 
Being future Yonko tax plays a great role and yes it's power scaling if anything.
The beliefs you have that Kaido BM are "confirmed" below all old gen like Shiki, Ray, Gaban who have yet to do or have major involvement in a big opportunity like God Valley is always a baseless surface lvl thinking.