People will submit creationist flat earther HEP theories-of-everything that explain why conservation of energy is optional and climate change is a conspiracy. Obviously, you want to reject those, or your journal's content will taken as seriously as internet forum conspiracy theories.
But all controversial ideas are divisive by nature. On any controversial topic, there will be people who think the idea is obviously wrong, no better than the flat earth, not worth the paper it's printed on.
And on the other hand, the people who defend their ideas the most vigorously can be the least interesting. Trying to reject, say, flat earther theories by proving them wrong is an endless fight, where every second spent fighting is your loss.
So, on what grounds can you reject papers, without immediately falling back on the generally accepted scientific consensus; the same that is used to reject all controversial idea?
What's your procedure to improve on traditional peer review? Where and how do you draw the line?