Hi
If you create more levels than needed, maybe the client needs to create more segments for material (table MVKE) and for customers (table KNVV) than the client would need.
In the other hand, if you create less levels (sales org, channel and so on) than client would need, maybe the client will find limits or troubles in the future for define with customizing tools new pricing procedures, access sequences for pricing, output types and so on (check in IMG the settings where these fields works) and it will be needed to do it with enhancements, userexits and so on.
Look for in table DD03L for tables T* and field VKORG. See the tables and maybe you will be aware about the points where these fields work.
I hope this helps you
Regards
Eduardo