From an owner of 5 Pro Duo's, here is a heads up of what you will face  :

Windows 10
The recommended mining driver 16.3.2     = Maximum 2 Cards, 3rd will BSOD.
The newer drivers which allow 3 cards     = Miner will mine at half speed.


Linux
simpleminingOS : after fiddling , got 3 cards running with no fan control or temps display what so ever, card were almost fried as there was no fan control. its resolved (sometimes) by using on-board vga and main display.
EthOS             : 3 cards will show but only 5 gpu's out of 6 will mine.


I asked Claymore and  EthOS Support, all agreed on one thing, this card have shitty drivers and they can't do anything from their side.