They also have to draw a card, which could play into any effects such as Sheoldred, the Apocalypse that are on the battlefield
We managed to fit about 20 dice into the middle tray more than enough
For your renewable sacrifice engines that's four sacrifices each turn, and a deathtouch blocker to trade up
Oskar, Rubbish Reclaimer This fun Dimir leader costs five for a discard of nonlands to be cast from your graveyard
Get rid of Flotsam and Jetsam for Peter Pan or Kit Cloudkicker Flotsam and Jetsam may have abilities that come into effect when they are both on the field, but you only have two copies each of these cards, making that scenario unlikely to happen
The only real downside here is that you cant activate this whenever you want, and its only one target at a time