There are only a few things I have to explain about Janemba's tiering. First, we must look at the fact that the mortal universe in Dragon Ball Z is a macrocosm. It was even stated to be one. Now, it has multiple definitons. The entire universe, or something massive in size. There are 4 QUADRANTS, QUADRANTS. NOT GALAXIES. Which people always seem to get wrong. The universe was even stated to be infinite in size. Janemba completely warped the entire macrocosm. Don't forget, Janemba was able to create a timeline in his hands, sucking in Ki blasts. If that dosen't change your mind, then listen to this. He creates portals in the universe at will, without breaking a sweat. Fun fact. Goku screamed so hard he shook the universe, including the afterlife. Wouldn't that make him a High 3-A? also, there is more! Heaven itself is as big as a universe, which he seemed to shake too, so either High 3-A Janemba or a 2-C Janemba.