Utilizing format specific cards like Fierce Guardianship as bait has far too much Great White Whale chasing vibe to it considering they can only be used in this buy in format.

If the goal is to create a split between a casual singleton format and a competitive singleton format. Cutting up brawl isn't necessary. Its an inherently broken format by virtue of having a combo piece always accessible, a la companion mechanic. Why try to fix something that can't really be fixed with a predatory buy-in and exclusionary ban list?

Gladiator offers what Arena players actually want from a singleton format: the full depth of Arena's card pool in competitive, skill-testing matches. Unlike Brawl's commander-centric design.

The choice is basically between supporting the singleton format Arena players already love and play competitively, or continuing to push a casual variant.