The short version of it is that there is a balance between how much time (read: mana, turns) one can spend accruing cards while contributing to the battlefield
C+ Deaths Approach This is an exceedingly efficient removal spell, but requires the rest of the Dimir package to provide the fuel
Here, my opponents decision to cycle a shark in to block my Familiar was punished by this sequence: play second Oven, sac second Familiar to get my third food, reanimate Feasting Troll King, cast Great Henge for just two mana, tap it to cast Uro and trigger Henge, sac Uro to second Oven (with his triggers on the stack) for two more food, use food to reanimate both Familiars (two more Henge triggers)
Milling someone for 10 cards almost always seems to help them out because almost every single Commander deck has ways to abuse the graveyard nowadays
Additionally, include utility artifacts like Obelisk of the Urd to boost the power of your Cat tokens, allowing them to stay on the battlefield after Brimaz attacks or blocks