I think its good to play three sometimes, mostly when your artifact count is looking low because of various colored cards in your deck, but I dont think Id ever play four again unless I was looking to build a dedicated swarm version
Its still great, but its a bit harder to pass with 6+ mana up in Commander these days
It lets you Sacrifice a creature at Instant speed, no extra tapping, mana, or resources required
It also makes the value from creatures with abilities more secure since youre not relying on hope and counterspells to untap with them
So, what is Myriad in MTG
(Note that if the front face is also a land, you couldn't have exiled it to begin with.) The set of creatures affected by Lightshield Array's last ability is determined as the ability resolves