Tsunade's strength doesn't come from chakra control. Sakura's does. Which also does not mean she is using little chakra to do it. In fact, it is more reasonable to assume the greater the feat of strength the more chakra she needed for it.
Which of course doesn't address the point of how does creating a gravity well that produces strong enough force to rip out mountains doesn't require lots of chakra when it is blatantly pointed out it does.
There was this one time in Rumbles when a guy was claiming Terrax didn't bust a planet because he was using his earth powers to do it.
This is reminding me of that time.
Also, don't get me wrong. I'm not saying chakra levels> All. There are different types of ninja and they all have ways of overcoming their weaknesses.
However, power types are power types, and arguing that a power type is not, in fact, a power type seems just silly.
Oonoki, Nagato, Naruto, A. They are all guys that use lots of chakra, to get lots of power out of the deal.
Kabuto, Itachi, Sasuke, Minato. They use clever techniques and have cool tricks to fight. Though it should be noted, even those guys have larger than normal reserves.