There are many/various builds.
So its hard for anyone to answer your question specifically.
There Are undead who runs
- just tomatos
- just turtle
- both turtle n tomatos
- just teleport and krebons
- all three , teleport ,krebons,pyscho commander
Its jus a matter of which way u wan to go into or which you prefer.
As for whether Dust tornado or nobleman extermination?
Most undead's side deck plays dust tornado or most deck's side deck play it.
creature swap is important on skill drain undead / undead beatdown/ligth beatdown.
As for undead synchro its up to u again ^^" .. your preferences.. it can be splashed in due to tomatos/turtle engines if you want