New info:
https://www.warhammer-community.com/2023/12/31/sunday-preview-prepare-to-enter-the-world-of-legend/
Supposedly these are all of the official base sizes:
Based on observation of pictures and/or previously confirmed sizes, I'm fairly confident about the following base sizes:
25mm square: Skeleton Warriors, Skeleton Archers, Tomb Guard, Infantry Heroes
40mm square: Ushabti, Bowshabti
25 x 50mm rectangle: Skeleton Horsemen, Horse Archers, Heroes mounted on Skeletal Steeds
50mm x 100mm rectangle: Skeleton Chariots, Sepulchral Stalkers, Necropolis Knights, Heroes mounted on Chariots (but not Settra)
100mm x 150mm rectangle: Settra, Bone Dragon
Confirmed models with bases I'm not sure about:
the Sphinxes: I think they're on the slightly wider new 60mm x 100mm rectangle, but they
might still be on the old 50 x 100.
Tomb Swarms: I think they're on 40mm squares, like the old ones, but they're new models and I haven't seen them next to anything else to compare sizes, so it's possible they could be on 50mm squares now.
Screaming Skull Catapult: Iirc this was confirmed to be returning (in resin, boo). This will probably be separate bases for the war machine and crew, with the crew on 25mm squares and the catapult on either a 50x100 or 60x100 rectangle, but that's just guesswork.
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Then there's completely unknown units - units which, as far as I'm aware, haven't been shown in any official
TOW photographs. These may or may not be returning at all, but I will speculate.
Nagash: likelyhood of returning - nill. He's not active at the time
TOW is set, certainly not in the areas the game is set. If he is somehow playable, he'll be on the 100mm x 150mm rectangle base he was originally sold with.
Arkhan: likelyhood of returning - nil. The
AOS model is on the wrong mount for the time period, and there's no current official model for him on his period appropriate flying four-horse chariot, requiring conversions, which GW does not encourage anymore. If he were playable, he'd be on a 25mm square on foot or a 100mm x 150mm rectangle on his chariot, like Settra. Thankfully generic liche high priest on foot or on bone dragon should be reasonable rules proxies.
Casket of Souls: likelyhood of returning - mid. A couple days ago I would have said high chance of returning. I mean, it's iconic, right? You could hardly imagine the tomb kings without it, and yet... I don't think it's been confirmed? It's not on the list of stuff that will be available for preorder on saturday (though neither will the catapult, and iirc it was confirmed). More significantly thhough, what official base size would you even put it on? It's ever so slightly too wide for the 60mm x 100mm rectangle, yet it would be positively swimming in the wildly oversized 100mm x 150mm rectangle, which is the only size up. Aesthetically it wants to be on like an 80mm or 100mm square, but that's not an option. They could just tell you to run it baseless maybe, as it's vaguely rectangular already? I don't know.
Tomb Scorpion: likelyhood of returning: mid. I don't think I've seen it mentioned, and it's theoretically kind of redundant with the stalkers and the new swarms in terms of burried harassment unit? But it's kind of iconic. If they bring it back, it could be on the same 50mm square it used to be sold with, though the 50x75 would be a bietter fit. It's honestly slightly too wide for that, even, but it would be swimming in a 60x100.
Carrion: likelyhood of returning: mid. probably on 40mm squares if they do come back, but I suppose they could be bumped up to 50.
Bone Giant / necroligh colossus: likelyhood of returning: low. Terrible model, redundant with the much better plastic sphinxes, etc. If they bring back the old model then it will still be on its old 50mm square. That said, there were rumors of a fully designed and never released plastic colossus/heirotitan kit way back in the day. If those were true and there were a new model yet to be announced, then it could be on another base, maybe a 50x75 with a striding pose? Sadly, if they were releasing a new plastic bone giant kit I think we'd have seen it already, so it's probably the lousy old resin guy or nothing, with nothing as a real possibility.
Heirotitan: likelyhood of returning: extremely low. GW just doesn't publish rules for units that don't have official first party models anymore, so I would say the odds are nil. But there was that rumor way back when of a finished but unproduced new plastic colossus/heirotitan kit, so I guess there's some hope? Again, imo we'd have seen it already if it were happening. And if a new model did appear, there's no telling what base size it would be on.
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I think that's everything. Let me know if I left anything out.