Sphere of Law prevents 2 damage from every red source they control, which meaningfully blunts Lightning Bolt, Incinerate, Shock, and even Sulfuric Vortex's upkeep trigger. Glowrider taxes their noncreature spells, so Lightning Bolt, Incinerate, Shock, Fireblast, Sulfuric Vortex, and Cursed Scroll all cost more at a critical point in the race (it taxes our own noncreature spells too, but it also gives us a 2/1 body). Their creatures like Jackal Pup and Ball Lightning are unaffected. Oath of Druids comes out because this matchup is a fast race where we need to stabilize, not set up a slow value engine, and if we control more creatures than they do, Oath lets them reveal into a creature for free. Naturalize only has a handful of targets here (Sulfuric Vortex, Cursed Scroll, Urza's Bauble) in a list that is mostly creatures and burn, so it's cut for the proactive anti-aggro package.