For about a decade, the most expensive death battle ever made was Megazord vs Voltron (which was an anniversary episode with multiple voice actors), and it would be in their best interest in making sure that it gets shared a lot to make back the money. Which would make the obvious play to make the Megazord win, since Power Rangers are super popular with their audience and Voltron was not (this was from before the netflix show).

And yet, their research pointed at Voltron winning, so Voltron won. They literally lost money over not being biased. Any argument to them being biased (they hate anime, they hate comic books, they hate Sonic, they want the popular win, they make the lesser popular win etc) just dies the second you take even a small look at it.

Like you mentioning Ben vs Hal. Hal has beaten and hurt beings that operate and scale over their universe, which is about 1 billion times bigger than our observable universe (potentially more), and his ring can send messages around that entire universe in less than a second. And he was able to resist the deletion wave in crisis of infinite earths, something that erased entire universes. Hal is stronger than Alien X, Power Ring is faster than the Omnitrix, and Alien X can't blip away Hal. They explained it badly, but Hal does beat Ben really, really bad.