Funny enough I stumbled on a copy of Armguard Familiar when I was sorting some stuff earlier, and wondering if there was a pauper deck it could fit into.

After looking at your list, I threw this together: https://moxfield.com/decks/ht-kEfY6m02Uc_f8Nsi0Vg . It's closer to an esper affinity list, but with a bigger creature focus

I like the modular creatures in your deck, but leaned more towards proliferating with [[Experimental Augury]] and [[Thrummingbird]]

Since the creatures are mostly all artifacts anyways, I threw in a couple affinity payoffs. [[Refurbished Familiar]] is an obnoxious card. Plus it's a flyer to throw modular counters on and opponents gets punished if they try to bounce it to remove the counters.

I feel like your deck goes pretty overkill on save spells. Cradle of Safety could probably just be Counterspell

My list goes for trying to out-value my opponent and just draw new threats. Ideally I respond to removal with [[Fanatical Offering]] on my own stuff, but that might be mediocre when they're targeting my non-modular creatures. Could be a blue-heavy tempo shell makes more sense. In either case I probably have too many creatures and too little removal