I´m working on this charakter at the moment … Base is coming from Poser …
No I added it through Cinema 4D into ZBRUSH with GOZ
Now my question … should I import the Base Modell First ?? And then the other as Subtool or …can I put them all together in One Mesh …??
Thanks for your Tips
Tobias 
It doesnt matter as to how you stack the order of your subtools. As long as you append all your subtools to your base mesh, then arrange the order using the up and down arrows in the geometry tab.
Hope this helps…
If you are working with levels of subdivision and need to be able to use blend shapes, morph targets, or continue editing your mesh in zbrush you will need to keep the base lvl objs seperate to ensure there is no accidental re-ording of vertex id.
Even the UVs may be disturbed by a re-order of vert id, it can happen that the UV layout looks the same but the actual UVs are jumbled.