They cant tap for mana without costing you some life but can be cashed in later in the game for a whole new card
We have already seen creatures, enchantments and one notable planeswalker printed on the opposite side of teased battle cards, including the Marchesa of the niche plane of Fiora or a towering apex predator from Ikoria - the designers said on the stream that theyre digging deep for planar callbacks as well as revisiting recent favourites in March of the Machine
I love this card so much, and it's a crime against humanity that I do not yet own it.
So, constantly blinking your scarecrows every turn with Conjurers Closet or Teleportation Circle is really likely to allow you to take over the game
However, this Orzhov commander does create its own payoff for the proliferation effect by creating Incubator tokens to transform into more Phyrexians
Estinien Varlineau Decks on EDHREC: 135 I could be wrong, but I don't think we've ever had a dragon tribal commander in Orzhov colors