At first glance, this deck may look like yet another version of Mardu Vehicles, but look closer.
Now look....more closelier.
Do you see it?
Not only is there not any black mana in this list, there isn't a single Vehicle in the entire list. Not even in the sideboard. In fact, there isn't even an artifact to be found here outside of the Clue that Thraben Inspector generates and the Thopter token from Pia Nalaar.
Instead, this deck gets to play a lot of good, cheap removal between Magma Spray, Abrade, and Harnessed Lightning to keep aggressive decks off its back. Pia Nalaar does a great job generating blockers against Zombies and Ramunap Red while still pressuring slower decks.
That combination of removal and cheap bodies lets you effectively protect its bevy of planeswalkers, from the ubiquitous Gideon, Ally of Zendikar and Chandra, Torch of Defiance to the perennially underrated Nahiri, the Harbinger. Notably, Chandra's mana-making ability casts all those cheap removal spells, leading to some excellent double-spell turn 4s.
Glorybringer and Archangel Avacyn both serve to turn the corner the turn after you untap with a planeswalker and fill that role admirably. The goal here is to tread water on the opening turns before seizing control with overpowered four- and five-drops and shutting the door quickly, before your opponents' synergies come online.
The biggest gain, however, is in the manabase. Mardu has historically struggled there trying to balance three colors, where here you get to play tons of basics and a full four Needle Spires with buttery-smooth mana.
Mardu Vehicles has been around for so long that similar decks have been dismissed for being a worse version of it, bit Mardu's success has dropped significantly since its height, so rethinking its core principles and updating it for a new metagame is an intriguing idea.