Damage dealt to a player causes that player to lose that much life
for just two mana, we have an artifact that can theoretically be played in any deck and has incidental graveyard hate
Each player thats getting attacked chooses any amount of creatures they control and puts those creatures in piles, equal to the number of creatures attacking that player
I think having a limited number of cards that can be face down creatures is a better experience overall, as you can make more informed decisions
For that reason, I think Eshki is the optimal Commander for the deck, but its close enough that I wouldnt fault anyone for going with Ureni instead
Saddle isnt a strong mechanic by far, so if youre unable to trigger The Gitrog, Ravenous Tides ability at least once, the deck becomes slow, clunky, and very ordinary