Okay, first question; Which variant are the Vanguard-Raptors, Annihilators, and Prosecutors? Their role varies depending on loadout.
As far as proxies/purchases go, the main thing I notice is that you're light on ranged units, and you could use a knight-incantor. Having 6 Vanguard-Raptors or 10-15 Judicators is really helpful for list building.
If you're looking for a competitive list, this is what I might try. You'd need another box of Vanguard-Raptors and have to use a Knight-Arcanum as a proxy (or just find one online for like ~ $10 USD)
Allegiance: Stormcast Eternals - Stormhost: Knights Excelsior - Mortal Realm: Ghur - Grand Strategy: Hold the Line
- Triumphs: Inspired Lord-Imperatant (175)* Lord-Relictor (145)* - General - Command Trait: High Priest - Artefact: Mirrorshield - Prayer: Translocation Knight-Incantor (125)* - Spell: Celestial Blades 6 x Annihilators with Meteoric Grandhammers (480)* - Reinforced x 1 5 x Liberators (115)* - Heavens-wrought Weapon and Shield - 1x Grandweapons 5 x Liberators (115)* - Heavens-wrought Weapon and Shield - 1x Grandweapons 3 x Annihilators (200)* 6 x Vanguard-Raptors with Longstrike Crossbows (480)* - Reinforced x 1 Celestar Ballista (140)* *Battle Regiment Holy Command: Thunderbolt Volley Total: 1975 / 2000 Reinforced Units: 2 / 4 Allies: 0 / 400 Wounds: 86 Drops: 1