You are correct that these are cabled more like a channel extended out from the controllers rather than a loop.  And yes, as per my  suggestion there would not be anything connected to the bus 0 out of the controllers, or to the output side of the 3.5" DAE.    I can understand not wanting to 'compromise' the factory drive placement if you aren't familiar with the product.   For the record, until the pools/RAID groups are defined, and Fast Cache is configured there isn't any physical reason that you couldn't move things around.  And in the current firmwares I actually believe that you can 'roam' drives around after configuration, but I have never had a reason to try that, and I wouldn't suggest doing it for fun.
Hi  Refer to the attached picture I have brand new box of vnxe3200 with two DAE  DPE : 25 x 900 SAS DAE 1 : 2.5" SAS  ( 3 flash + 6 sas) DAE 2:  3.5" NL-SAS ( 9 x 4TB)  I am just wondering is there any recommendation from EMC which DAE should be connected first with DPE ? For instance port 0 of DPE  should always be connected with SAS enclosure  or NL-SAS enclosure ?   I have read different docs so far and there is no such discussion but I would like to double check here on the forum.  thanks  
Connecting VNXe3200 DPE - Recommendation