We tried the rules for the zombie titans in a scenario similar to what I want to do for the Mortis game, except on a smaller table.
We started with 1000 pts of traitor stuff against 1000 pts of loyalists. The loyalists could then bring on 500 pts every turn and the traitors could bring on 3d6 x 100 pts of stuff each turn.
As expected the zombie titans didn't last long. Without shields titans are pretty vulnerable and these already had damage on them on top of the lack of shields.
They shuffled forwards, fired the weapons they could and managed to bleed some shields from the one Warlord.
It wasn't long before the first one of them was down. One round of shooting from a Reaver brought down the Solaria Warhound without it even firing a shot.
The two Reavers lasted until the second turn when a second Astorum reaver arrived and put the boots to one of the zombie reavers, shooting its head clean off.
The Astorum Warlord took out one of the Mortis Warhounds while the two Astorum Warhounds finished off the last of the zombie titans. They didn't do much damage but it seems they drew enough fire.
The Mortis warlord managed to take out the first Astorum Reaver, while the remaining Mortis Warhound ran up on the Astorum Warlord firing point blank with both plasma guns. The Warlord died, firing wildly and then falling on top of its killer, crushing it, so that Warlord ultimately accounted for both Mortis warhounds.
After it arrived the second Astorum Warlord contributed almost nothing to the loyalist cause. After knocking the shields from the Mortis Warlord it failed to connect with 5 of 6 shots from Volcano cannons and fell victim to a charge from traitor Atrapos knights.
The Mortis Iconoclast arrived and charged straight across the battlefield, ignoring all incoming fire and only pausing to crush two loyalist knights that had charged it.
It made it to the enemy deployment zone, ripping a loyalist Reaver in half when it got there.
Another loyalist reaver fell to the Mortis Warlord and with that the game was over. The loyalists had lost about 1500 to 1000.
Overall the zombie titans worked like they seem they should have worked. They absorbed some hits, dealt out some damage but were not much of a threat overall. We use a slightly different catastrophic damage table which allowed them to do more morale damage than physical damage on the higher rolls. They still fell over and wild fired as other titans though.
It was a pretty fun game. I'm going to take some time off from zombie titans now though as I prepare for Spring Necromunda league by building a bunch of terrain.