If you look back at the "classic" TD period between "Atem" and "Encore", it's worth noticing the division of labor going on. Check to see this in action. Froese would mainly stick to leads, while Franke and Baumann are working out the complex backdrop with sequencers and polys. Franke's rig was primarily Moog, while Baumann used a composite of Moog and PPG modules. Also, they almost certainly have a central clocking system for all of their synths, given that this was definitely in use by the time of "Encore" as it appears in that album's credits.
In the present day, this is actually a lot EASIER than one might think...but you gotta know your tech! Fact is, you can cobble up just as complex a sequencer system in VCV or with VSTs in a DAW, and by using some method of sending CV/gate/triggers to your synths, you can have this for far less than a pile of Moog 960s. Or make it happen in VCV, if your machine's up to the task.