Re: sound change question

I'm having some issues here.

In my conlang Seinunjdjé, having the following phonoeme inventory,

Consonants:
p b t  d         t` d` k g
f v T  D s z S Z s` z` h G
  m nh n            n`    N (allophonic with /n`/)
                 r  l`
  w            y
(the /l/ phoneme is realized as retroflex, alveolar, or velar depending on
environment, but the phonology treats it like a retroflex.)

Vowels:
i i:      u u:
 e e: &: o o:
     a a:

I'm trying to evolve this series of fricatives: (where all voiced are
followed by ^h)
f v T D s z S Z s` z` s\ z\ C J h
and I'm wondering how four of those can plausibly come out of effectively
nowhere.  I'm thinking that neighboring stops will be major players here,
but I can't for the life of me work out how.

Idea 1:
The affricates /tS/ and /dZ/ can become the new /S/ and /Z^h/, while the
fricatives become /s\/ and /z\^h/.  Palatals appear in the split that
creates the series.


(Incidentally, this plan is for purely aesthetic reasons.  I like the
fricative characters and am looking for excuses to use them.)

---
Shreyas