Would Panharmonicon give my Myojins extra divinity counters?
Panharmonicon will not double the divinity counters on any of the Myojins because the ability that adds a divinity counter is not a triggered ability. Myojin of the Seeing Winds' ability says


  Myojin of Seeing Winds enters the battlefield with a divinity counter on it if you cast it from your hand.


This is a static ability that creates a replacement effect of the type described in rule 614.1d that modifies how the creature enters the battlefield.