The difference in wording on a card that makes it from a must have 4 of in most decks.
If The new Hierarch say's "Vigilance, Tap to add 1 color of any mana to your mana pool; Renowned if this creature deals combat damage to target player put a +1/+1 counter on it" It is a better Birds of Paradise, as is it's junk and shouldn't be played.
You literally need a way to A) make sure he comes down turn 1 every time, B) make sure he hits just so you are sure to get your mana, and C) keep him alive long enough to use it, at that point I'm just playing Shaman of Forgotten ways if i need ramp, at least he really jumps (3 to 5) and has an alternate win condition.
This post just got my green white aggro deck mind thinking though
Turn 1 Honored Hierarch, Turn 2 Gideon, Hierarch, Turn 3 Swing (maybe keep up dromoka's command), Gideon Flips, Untaps a Hierarch, pray they don't have languish