help / opinions for Myr Artifact Arcum Daggson

I've been modifying my first EDH deck for a long time now, the Myr Arcum deck I want it to be 75% competitive?

Basic idea is I can get around 20 flying 2/2 indestructible myrs out turn ~7 using Arcum, Myr Incubator, and Eldrazi monument. After that I can protect my artifacts with darksteel forge, or use coat of arms to make them 20/20s, or what have you.

I'm sorta trying to avoid direct damage infinite wambo combos. I'd love to speed up or better the myr synergies to make it more competitive.

Assume budget isn't much of an issue, as I'd be continuing to pick up cards slowly over time.

Would love feedback and input on card suggestions, thanks!