Shimano Shifter cable set polymer with crazy number of ferrules

So I use the Shimano polymer shifter set that includes a huge number of ferrules and asorted items to use depending on situation. Well my 6800 group shifts great almost by itself but the shifter cables at the head frays after about year and I put on cables on.

My question is that shimano gives you all these various parts and I assume you don't use them all depends on the situation. In my case a Habanero Ti road with exposed cables. I know the metal ferrule that does into the derailleur barrel adjuster that is the given. I also know there is one used at the shifter exit going out and down under the bar tape and housing. Otherwise I am lost as to what to use other than what works. Should just avoid nylon stuff.

Now the other thought is to simply buy some shimano bulk housing and use the regular die-drawn cable without the polymer coating. I don't want to experiment what works?

Deacon Mark