Need to Randomly distribute a list of items in MS Excel 2013

I have a list of machines(>50 Nos.) and have some supervisors (4 to 5) , now I want to randomly distribute the list of machines for some audit purpose as per their monthly work schedule.

You can see the attached xl file (No VBA) for details. 

 

Somehow I am able to distribute it randomly but some of the machines from the list are missed due to the weekly off of the supervisor.

 

The value I used for index match is the column numbers, I also tried a few other things but think this may be the simplest one.

 

Can you help me out!? "Using Excel 2013 ".