Not only do these require you have a creature in play that's bigger than the threat you want to remove, but they also have the failcase of completely fizzling out if your creature gets removed in response
Each meld pair consists of two specific cards whose back faces combine to form one oversized Magic card face: Midnight Scavengers and Graf Rats meld to form Chittering Host
Although that said, I'm thinking this might be pretty fantastic in a Derevi, Empyrial Tactician cEDH deck
Im not a believer in proliferate as a reasonable way to build around energy, so Im very skeptical even of the best proliferate cards, including Atraxa, Praetors' Voice, even though Atraxa seems to have been the most popular energy commander until recently
For example, The Great Henge has already been reprinted twice its release in 2019, and it still demands a hefty price