1-drop choice is mostly a preference. I like to have 4x Dauntless Bodyguard and 4x Legion's Landing. Other than that I favor Law-Rune Enforcer, Skymarcher Aspirant, Snubhorn Sentry and Hunted Witness over other 1-drops.
I think White has a lot of strong 2-drops and, on the contrary of most popular builds, I still believe playing ~7-8 is good idea (a lot of people cut them for more 1-drops). That way you have much better topdecks than normally.
I wouldn't play more Gideon Blackblades mainboard than 1. He's very weak vs aggro decks when you're behind. Imagine playing him vs mono R with no creatures on board.
The same would be Unbreakable Formation. On paper its great vs creature matchups and obviously it's good to swing for free. On the other hand topdecking it on empty board is really unwanted and having 2x in opening hand is a nightmare. I found myself sideboarding it out more often than not.
Also Conclave Tribunal is the removal of choice over Baffling End and Ixalan's Binding - it catches everything and thanks to the amount of creatures you can generate you can cheat it as soon as turn 3.