Arcane Question: Why MoA > RoP?

[Eedelia]

It's my understanding that MoA gets a damage bump from RoP if cast while standing on the mat. I always cast RoP > MoA but all the guides for rotation that I see are MoA > RoP. Am I missing some nuance here?

[Deckzor]

The important thing with MoA is the Explosion at the end.
You safe ~2 Secs in RoP for an extra AB or AM if you cast MoA first. And thats a DpS gain over 1-2 ticks of the Mark