Correct way to populate Harness Package in Vehicle Assembly

Now this gets tricky for me as I move ahead with Cabling.

I have: 

= The whole vehicle assembly,

          -Sub assembly

                  -Main Parts

                           -Screws /nuts / bolts

Then comes HARNESS at the end. 

Now I have 1098 Harnesses in this BEAST.

What is the best way to organize my HARNESSES?? See attached image.

What should be my approach?

I have to get it right from get go or will waste 10x ::::))))

If you guys can make me sleep well for this weekend, nothing like it 🙂 

THANKS IN ADVANCE FOR YOUR TIPS!