Two differences in this plan to Shard's.
1. Trolls don't get fatigued so there is absolutely no reason whatsoever to have them rest. Because of this, they will be active for a full turn instead of 3/4 turn.
2. Having the Sirens do something. Killing and eating daemons, specifically.
[X] Plan Sirens vs Daemons
-[X] Rely on Regulars- This force should be able to easily handle the enemy stormtroopers and slow down Astartes and Sisters as well as inflict some damage to them. This will make a slight impact on your reserves.
-[X] Deploy half your elites to the field and keep half in reserve. -This will leave you with a significant reserve force of elites while reinforcing your main combat zones.
-[X] Have the defences on the inner side of the districts stronger-By deploying a greater number of your elites to the inner walls of the districts you should be able to slow the Chaos Space Marines and Sisters of Battle significantly.
-[X] Psykers
--[X] Scry and Fry (Psyker Choirs)
---[X] Ridcully, Xavier, 1st Pyromancy Choir (1/2 Turn), 1st Divination Choir + 2nd Pyromancy Choir (1/2 Turn)
--[X] Support Troops/Fortifications
---[X] Both Biomancer Choirs (1/2 Turn), 1st Telekinetic Choir (3/4 Turn), Troll Geomancers
--[X] Dispel/Countertelepathy
---[X] Lulana, 1st Daemonology Choir (1/2 Turn), Tamia, Both Telepathy Choirs (1/2 Turn)
--[X] Anti-Daemon
---[X] Sirens (focus on Seraphim and up)
-[X] Other
--[X] Support the Sirens with military. Keep their unfavoured enemies off them so they only have to fight daemons.
--[X] Lure Seraphim and up into a trap where the Sirens can consume them.
--[X] Continue EW on enemy.
--[X] Leave the Black Crystal Necklace with Tamia.
--[X] Lend Black Crystal Sword to Jacob
--[X] Eliminate Sorceror Lords and Chaos Lords joining the pushes.
---[X] Primaris Executioner Forces, Psyker Regiments, Psyker Squads, Black Irons, Psyker Hunters, Witch Hunters, Last Hunters, Jane, Aria, Jacob with 2nd Daemonology Choir and 2nd Telekinetic Choir support.
--[X] Ambush small groups of Astartes at a time, whittling away their numbers.
---[X] Trolls, Phase Tigers, Veteran Infiltration Psyker Regiments with 2nd Diviner Choir support (3/4 Turn).
--[X] Slowly give away as appropriate to prevent Abomination from becoming too desperate, if we succeed excessively.