Army build and tactics against Slaves to Darkness

[Balthasar]

Hello,

I will soon face my friend in an epic and iconic battle: Slaves to Darkness vs Stormcast Eternals (3000 pts).

Here is the build that I planned to play.  I have a lot of figurines still in reserve like the rest of the Dominion box, 5 judicators and Lord Celestant on Stardrake.

Allegiance: Stormcast Eternals
- Stormhost: Hammers of Sigmar
- Grand Strategy: Hold the Line
- Triumphs: Inspired

Leaders
Yndrasta the Celestial Spear (300) in Vanguard
Lord-Arcanum on Gryph-Charger (215) in Warlord
- General
- Command Trait: We Cannot Fail
- Artefact: Arcane Tome (Universal Artefact)
- Mount Trait: Aethereal Stalker
- Spell: Stormcaller
Lord Imperatant (160) in Warlord
- Artefact: God-forged Blade
Lord-Ordinator (150) in Grand Battery
Knight-Incantor (130) in Warlord

Battleline
5 x Sequitors (130) in Hunters of the Heartlands
- Stormsmite Mauls and Soulshields
- 3x Stormsmite Greatmaces
5 x Sequitors (130) in Hunters of the Heartlands
- Stormsmite Mauls and Soulshields
- 3x Stormsmite Greatmaces
5 x Sequitors (130) in Hunters of the Heartlands
- Tempest Blades and Soulshields
- 2x Stormsmite Greatmaces
5 x Judicators (150)
- Skybolt Bows
- 1x Shockbolt Bows

Units
5 x Evocators (225) in Vanguard
- Spell1: Lore of Invigoration: Speed of Lightning
5 x Retributors (205)
- 2x Starsoul Maces
3 x Annihilators (190) in Vanguard
3 x Praetors (155) in Warlord
2 x Concussors (235) in Vanguard

Artillery
Celestar Ballista (120) in Grand Battery
Celestar Ballista (120) in Grand Battery
Celestar Ballista (120) in Grand Battery
Celestar Ballista (120)

Core Battalions
Warlord
Vanguard
Grand Battery
Hunters of the Heartlands

Additional Enhancements
Artefact

Total: 2985 / 3000
Reinforced Units: 0 / 4
Allies: 0 / 400
Wounds: 158

 

My strategy is to hurt him from a distance and with magic, while I would hold a solid line thanks to the paladins, the sequitors and Yndrasta.  I know he will most likely play with Archaon and the Varanguard.

What do you think of my build?  Do I have to make any changes? Do you have any tactic advice for the battle?

Thanks you