
The battle unfolding in full colour: See army lists above for abbreviations!
Sorry for not taking notes and no useful pictures in T2, but we were in some hurry as my opponent wanted to go to bed not too late (has kids) and I had to pick up my army at the Eldar players place, who had conveniently muted his phone, worked all night and slept all day.
Anyway, events:
T1:Orks win strategy, start ground attacking the PT, causing 4 damage, forcing it to Marshal&Move, clearing all BM.
Stompas go on OW, 2nd Doomwings ground attack KoS1, small F/Bs intercept them, downing one.
Renegades stall by going on OW again. KoS2 doubles forward, out of their LoS.
LoC2 advances to fire on them, killing one with its Withering Gaze.
Landa ground attacks KhM.
LoC1 doubles and immolates a Skorcha from KoS1.
Landa strafes KhM
BT marches forward, ending in front of KoS1.
BGM1 advances and kills BT.
LoB marches towards the same position.
KoS1 holds and removes BM
Orks have no more activations.
Juggers march from gate, lose 1 to BGM2´s OW.
NuM march into charge range of BGM1
KhM marshall& move deeper into the Cathedral
T2Chaos goes first.
LoB doubles and shoots at KoS1
NuM engages intermingled BGM1 and KoS1 - Gunz are wiped out and KoS is reduced to 2 Skorchas and flees towards and beyond the Ork blitz.
BGM2 sustain into the Juggers, killing 2 and breaking them, they "retreat" forward and left.
Stompas do something ineffectual, can´t remember ÂÂ
PT doubles forwards and shoots at BGM1 and the broken KoS1 behind it is caught by the Plague Mortar as well. BM on the Gunz, one Skorcha lost to BM.
Lesser F/B finish the PT.
LoC1 doubles and blows a Stompa apart.
KoS2 backtracks and fires ineffectually at Juggers

...through all the smoke and fire...
LoC2 doubles and takes out a Skorcha from KoS2
Large F/B descend on LoB but fail to damage it
Rest is some strafing Landas, KhM covering both objectives around the Cathedral anyway, and lastly the Flamers of DHTz marching from the Chaos Gate into FF range of the Stompa Mob, in a daring attempt to gain BTS next turn!
T3:Orks win, of course, and send a Landa right into the Flamers, it is a vicious fight and the daemons are wiped out at some loss to the Orks. what´s worse, the Warband is now intermingled with the Stompas.
Orks retain and break LoC2 with F/B.
LoB advances into FF range of the Stompas, I think killing one.
LoC1 engages the intermingled Warband, Landa and Stompas, after two turns of heavy fighting and thanks to the LoBs support fire, good saves, inspiring, BM and Tzeentchian twists of fate the greater daemon wins, destroying the Landa, killing another Stompa through resolution and having taken "only" 2 damage in the process. The orkish flank has just collapsed, which will decide the game.
The rest is something of a maneuver/mob up operation, with Chaos holding a significiant activation advantage and having many more ground assets. The Orks failed to rally the Stompas and Warband after T3, which severely limited their options.
The 2nd Landa will eventually assault into the Renegades sitting on the Chaos Blitz and wipe them out after I failed 8 out of 9 4+ saves, but with the NuM marching into charge range of the remaining BGM2 on the ork Blitz and with Chaos winning strategy in T4 there is little the greenskins can do to prevent Chaos from gaining T&H and Blitz vs Blitz for a 2-1 win with air attacks being insufficient to break the khornate Mutants sitting in the Cathedral on the T&Hs.
Conclusions:
I got lucky in the right moments, winning initiative when I really needed it and generally passing critical activations.
The list played very well, in a sense it is LatD on speed, the GDs are very focused formations which can perform quite well with no Cultists to slow them down. I suffered some attrition closing in (the Plague Tower and the Bloodthirster) but all said and done I think the Orks should have concentrated on the Lord of Battles instead, which was BTS and crucial in turning the flank.
Drawbacks of the Horde are somewhat brittle formations (the lone GDs) and lack of ground flak: Ork air kept attacking me without needing to roll, I used the Doomwings for some CAP early and late in the game (to BM the air assaults), ground attacking in between. I really felt at the mercy of those F/Bs...
As I said I was lucky with activations: My general experience with LatD has me preferring traitor IG-gear mixed with the Coven to get me some shooting as they fail their activations all the time, and pure assault formations stacked with summoning are close to useless when you hold instead of engaging.

Final positions, orkish Blitz area

The End, Cathedral T&Hs in Chaos hands, orkish air.