Son of Dathomir and Dark Disciple

I always assumed that SoD and DD took place more or less at the same time, but I just realized it’s not possible because Dooku was with Maul for most of SoD, while he was with Vos for most of DD. So what’s the timeline of these two events? Did SoD occur after DD? Or maybe SoD took place shortly before the first duel between Vos/Ventress and Dooku?

They're both set in 19BBY, but I'm not sure what the overlap would be.

Although as the Thrawn novels have shown us, seemingly big events like that can be crammed into relatively brief periods of time. For example, the entire Treason novel is set in between Rebels S04E10 and the finale.

I read DD takes place a few months before ROTS.

Well, the events of DD take place in several months/1 year. It definitely ends not long before RotS

I always kind of assumed DD was post-SoD, but I can't think of a particular reason for why. It's been too long since I read it.

Now that I think about it, there probably isn't an overlap between these stories at all.

If Galactic Maps is any indicator, then Palpatine's battle with Maul/Savage in The Lawless occurred toward the beginning of 19BBY, which means that SoD took place immediately afterward. Ahsoka's trial occurred some time after the events of The Lawless/SoD, and DD was set after Ahsoka's trial(Asajj was obviously still alive, and Barriss' betrayal was also mentioned in the novel.)

So the timeline of events would be:
-The Lawless/SoD.

-Ahsoka's trial.

-DD

-TCW S07(final arc).

Makes sense, gg Galan