Deathbattle is wrong rofl. Everybody in japan knows that.
They know nothing about DragonBall Z. Their are just stupid Americans. Look what they explain why Goku would lose too superman. It doesn't make sense. They mention low power levels of Goku in the DragonBall Z series. They focused on Goku's powerlevel when he was not even on his max. Like Dragonball z GT for example.. DBZ GT is way too powerfull for superman. Superman would have troubles with Piccolo already.
They are not completly honest.
I was a fan of Superman, I had alot of Superman action figures. BUt I've never ever saw in Justice League a power level like this -
https://www.youtube.com/watch?v=1Uq1hr3BkeE
http://1.bp.blogspot.com/-azXtOSZ0l8..._you_didnt.gif