It breaks even in terms of how much total additional power and toughness you get with a traditional Anthem at three creatures, but giving one of them +2/+2 instead of +1/+1 can really change the texture of combat, and things get out of control once you have four or more creatures
Losing a partner ability during the game doesn't cause either to cease to be your commander
Poisoned Knowing the rules around the Poison status is vital, as its almost certainly the most common status condition in the game
On the other hand, I'm not convinced about its playability if we don't have access to a stacked hand
Anathemancer This is Price of progress
Often the engagement then actually gets in the way: you end up ticking off specific tasks within a match, rather than playing the game itself for its own good, and only come back for extrinsic rewards: skins, XP, packs, or whatever else