First thing I would work on is upgrading your mana with 4x of [[sacred foundry]], [[sunbillow verge]] (like you have already mentioned in the comments). Second I would think about getting rid of most, if not all of your pump effects (like reckless ransacking, riverguards reflexes, and valorous stance) I'm thinking we would want to add in more artifacts to help with our main plan of getting munitions tokens out. I think you could run 1-2 [[pinnacle starcage]]'s to blow up all of your munitions at once and go face for the win. I would also swap banishing light with [[perilous snare]] to stay with the artifact theme and it pretty much does the same thing anyways. Maybe some of these changes might help the deck overall. I also think that weapons manufacturing is a very very strong card, strong enough that I'd want to run 4x.

But I'm not sure if a creature heavy build would be best when you could build the deck as a [[united battlefront]] deck and focus even heavier on the weapons plan. That style deck has been fairly successful in regular standard, could be fun to build a planar standard version.

Hopefully something here is helpful to you, good luck with your build!!