I wish I could play more than four
There is a fair amount of crossover here with the white-black sacrifice decks, which is helpful when building a deck because there are more black cards that work for both
the card number can be found in the bottom left of each card, with the format being X/204 (X is the card number, from 1-204), then EN (the card language code, for English cards) and finally, the set number
The only risk is getting your biggest creature removed in response (or getting its power shrunk, but no one plays those effects, right?)
Just playing defensively and looking to trade cards with your opponent will naturally fill your yard and charge up payoffs like Exdeath, Cloud of Darkness and The Final Days
As a side note, both of those commanders being Bant colors means that they get access to Finest Hour