Versatility is the main key for reaching skyfather levels. If you don't have it, you don't belong. You can be as powerful as you want physical, if you are not versatile enough to contend with a true skyfather, your chances are gone. You can have the power but you also need the versatility. Example...Umar is a true high end skyfather. She admitted on panel TWICE that she didn't have the power to defeat the Mindless ones. Not only did Hulk defeat them at WWH levels...when going into full, blown, WBH mode, he killed the Mindless Ones with a back lash of a single punch. That wasn't just it. He killed 2 physical high Herald, a being that was amped enough to destroy Worlds and he destroyed a being that over powered Merged Hulk with one arm and defeated Surfer at the same time. He killed all of these beings without even touching them and being at couple of 100 ft in the air. That's not it...he took out the planet and two moons (remember, single punch, also remember, a high end skyfather admitted she couldnt take out some of these beings under her own power and Hulk killed them without even touching them).
Let's also not forget that the current/recent depictions of the Mindless ones was capable of shrugging off attacks from high Heralds like nothing. To the point that Nova himself had to flee because his power output wasn't enough to even damage them.
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They were also capable of walking in neutron stars without even feeling it.
[url]http://i287.photobucket.com/albums/ll121/kingaholu/MindlessonesNeutron.jpg
The heat from Hulk punch killing these beings should outright be intense as hell. After all of this...I still wouldn't put Hulk in the skyfather tier because even though he is a physical monster, he is missing a lot of things. I wouldn't put Amazo either or Strange.