Hey,
first of all, I think you got to much artifact good stuff for "absolute control" with
memnarch. I would expect more stuff to support him in stead.
then, have you already got
Command Beacon? if not, I reccomend to replace it, since its very expensive, and there are other cards, that you could buy in stead which would help the deck more.
The
urza lands seem perfect for
memnarch, since you want alot of mana, but you got no tutors to get them. So you will very rarely collect all 3. Just checked without additional draw, the chance to get all 3 until turn 10 is ~0.3%.
I've got a
memnarch deck myself, maybe you find some inspirations in there:
https://deckstats.net/decks/112190/1058554-memnarch-v2/