Personally, I think Lanturn got chosen for completely different reasons, but it's not my place to make guesses as to why something was picked. Anyway, I think there's another Pokemon we're forgetting about: Rotom-C. If it's Scarfed and runs full coverage (as in VS, Leaf Storm, TBolt, HP Fire) nothing is safe, even if we added something like Braviary. I know we're slow as shit right now, but I'll worry about that in our last entry. Instead, I'm going to suggest this guy right here as it can beat Lilligant, draw in Flying-type moves for Omastar to setup on, and decimate any special wall that thinks it has a chance:
Gallade (M) @ Lum Berry
Trait: Justified
EVs: 200 HP / 252 Atk / 56 Spd
Adamant Nature (+Atk, -SAtk)
- Swords Dance
- Drain Punch
- Psycho Cut
- Night Slash
Bulky SD Gallade does quite a few things for us. For starters, it's a good offensive check to Lilligant, Rotom-C, and Sceptile as none have a chance to OHKO with their standard sets. (Grass Gem Lilligant beats Gallade, but we can always scout for that with Escavalier) Gallade gives us a physical sweeping option that can capitalize on Escavalier's wallbreaking prowess as well as beat down the Steel-types that plague Escavalier. Drain Punch keeps Gallade in good health and beats down most physical walls (good thing for Escavalier) Psycho Cut takes out Qwilfish, Amoonguss, and Roselia, the latter two of which may try to test their luck with Omastar's Ice Beam. Night Slash beats Slowking, Uxie, and Mesprit. Considering Specs Slowking is actually a p. major threat to this team right now thanks to its coverage on, well, everything we have and it still survives +2 HP Grass from Omastar, this is a pretty big deal imo. Here's the calcs against the Grass-types that are giving us issues right now:

Gallade (M) @ Lum Berry
Trait: Justified
EVs: 200 HP / 252 Atk / 56 Spd
Adamant Nature (+Atk, -SAtk)
- Swords Dance
- Drain Punch
- Psycho Cut
- Night Slash
Bulky SD Gallade does quite a few things for us. For starters, it's a good offensive check to Lilligant, Rotom-C, and Sceptile as none have a chance to OHKO with their standard sets. (Grass Gem Lilligant beats Gallade, but we can always scout for that with Escavalier) Gallade gives us a physical sweeping option that can capitalize on Escavalier's wallbreaking prowess as well as beat down the Steel-types that plague Escavalier. Drain Punch keeps Gallade in good health and beats down most physical walls (good thing for Escavalier) Psycho Cut takes out Qwilfish, Amoonguss, and Roselia, the latter two of which may try to test their luck with Omastar's Ice Beam. Night Slash beats Slowking, Uxie, and Mesprit. Considering Specs Slowking is actually a p. major threat to this team right now thanks to its coverage on, well, everything we have and it still survives +2 HP Grass from Omastar, this is a pretty big deal imo. Here's the calcs against the Grass-types that are giving us issues right now:
+1 252 SpA Life Orb Lilligant Giga Drain vs. 200 HP / 0 SpD Gallade: 188-224 (57.49 - 68.5%) -- guaranteed 2HKO after Stealth Rock
+1 252 SpA Lilligant Giga Drain vs. 200 HP / 0 SpD Gallade: 145-172 (44.34 - 52.59%) -- 81.64% chance to 2HKO after Stealth Rock
252 SpA Rotom-C Leaf Storm vs. 200 HP / 0 SpD Gallade: 175-207 (53.51 - 63.3%) -- guaranteed 2HKO after Stealth Rock
-2 252 SpA Rotom-C Leaf Storm vs. 200 HP / 0 SpD Gallade: 88-105 (26.91 - 32.11%) -- 2.17% chance to 3HKO after Stealth Rock (this is basically to show Rotom-C needs max damage on both Leaf Storms to successfully beat Gallade. Otherwise, Drain Punch gets Gallade healthy enough for a -4 Leaf Storm)
252 SpA Rotom-C Thunderbolt vs. 200 HP / 0 SpD Gallade: 118-141 (36.08 - 43.11%) -- guaranteed 3HKO after Stealth Rock
252 SpA Life Orb Sceptile Giga Drain vs. 200 HP / 0 SpD Gallade: 122-146 (37.3 - 44.64%) -- guaranteed 3HKO after Stealth Rock
252 SpA Choice Specs Sceptile Leaf Storm vs. 200 HP / 0 SpD Gallade: 262-309 (80.12 - 94.49%) -- 6.25% chance to OHKO after Stealth Rock (this one was kind of extreme as Sceptile will usually pack Life Orb, but even still, the chances are heavily in our favor if it runs Specs)
+1 252 SpA Lilligant Giga Drain vs. 200 HP / 0 SpD Gallade: 145-172 (44.34 - 52.59%) -- 81.64% chance to 2HKO after Stealth Rock
252 SpA Rotom-C Leaf Storm vs. 200 HP / 0 SpD Gallade: 175-207 (53.51 - 63.3%) -- guaranteed 2HKO after Stealth Rock
-2 252 SpA Rotom-C Leaf Storm vs. 200 HP / 0 SpD Gallade: 88-105 (26.91 - 32.11%) -- 2.17% chance to 3HKO after Stealth Rock (this is basically to show Rotom-C needs max damage on both Leaf Storms to successfully beat Gallade. Otherwise, Drain Punch gets Gallade healthy enough for a -4 Leaf Storm)
252 SpA Rotom-C Thunderbolt vs. 200 HP / 0 SpD Gallade: 118-141 (36.08 - 43.11%) -- guaranteed 3HKO after Stealth Rock
252 SpA Life Orb Sceptile Giga Drain vs. 200 HP / 0 SpD Gallade: 122-146 (37.3 - 44.64%) -- guaranteed 3HKO after Stealth Rock
252 SpA Choice Specs Sceptile Leaf Storm vs. 200 HP / 0 SpD Gallade: 262-309 (80.12 - 94.49%) -- 6.25% chance to OHKO after Stealth Rock (this one was kind of extreme as Sceptile will usually pack Life Orb, but even still, the chances are heavily in our favor if it runs Specs)