The difference between these cards and Game Changers is that Game Changers, while strong, are labeled Game Changers with Commander's social setting in mind
Any player who wants to respond needs to do so before the trigger resolves
Ferrous is even more powerful in the 99 of Multicolor Matters commanders that have access to more colors like Rienne, Angel of Rebirth, Niv-Mizzet Reborn, and my personal favorite, Ramos, Dragon Engine, which I love building as Lucky Charms
The spells mentioned above won't be very good without a way to load your graveyard with threats
Turn those extra Treasures into +1/+1 counters and beat down, or ramp into something else that will, presumably, also beat down