Can one card change a deck to a different bracket?

I know that the bracket system is still in beta and that deck building sites like Moxfield aren't the end all-be all on the subject, but I came across a something that really makes me wonder how flexible these bracket definitions should be.

I just slapped together a [[Krenko, Mob Boss]] deck just to do something with my goblins and good stuff red cards. A super budget first draft of a build but Moxfield marked it as a B4, which surprised me. In checking the reasoning, it cites my [[Magus of the Moon]] as the OP card, and without it the deck sits at a B2, which is what I was initially expecting.

This surprised me that a single card could elevate a deck two whole brackets. I have two other decks each with only a single MLD piece, and I tested those to see where they'd lie without them.

I have a [[Tivit]] deck that's fairly strong and Moxfield would consider it B3 if not for the [[Winter orb]] pushing it to B4.

I also have an [[Etali, Primal Conqueror]] deck that's never won a game that Moxfield would rank as B3 if not for the [[World slayer]] pushing it to B4.

Ultimately, I understand the reasoning as to why MLD is considered too much for lower powered brackets, and frankly I don't mind my Tivit and Etali decks getting bumped to B4. But Krenko moving two whole brackets because of one piece of MLD feels like a bit much.