k' > ts > c-hachek order of changes?

[ECOLING at aol.com]

The following mention got my attention:

>          k'  >  c  >  ts
>          g'  >   j  >  dz

I have come to suspect / believe / almost to argue evidence
that the normal development is rather the reverse, phonetically,
that we more commonly have (universally?)

k' > ts > c-hachek
g' > dz > j-hachek

because the /ts,dz/ require more effort,
reflect better their origin as a *fronted* tongue-body production,
with the flat front of the tongue rather than the back contacting
the roof of the mouth,

whereas the grooved <c-hachek, j-hachek> are more relaxed,
with less fronting or raising of the heavy body of the tongue,
but still an affricated acoustic effect,
so presumably a later substitute for /ts,dz/.

The theta <th> is also I believe often a reflex of earlier /ts/
rather than only via /ts/ > /s/ > "th".

Does this make sense to anyone?
Is there evidence from Slavic,
which shows both reflexes for velars?

Is there evidence in the Indo-Iranian group for
this other order of changes?
The only thing I can think to add at the moment is a vague memory
that in the NW part of India there are reflexes /ts,dz/
where we otherwise expect (from Sanskrit) the
grooved <c-hachek, j-hachek>.
The basic letters of Tibetan also have these values /ts,dz/,
and a diacritic is used to represent the Sanskritic <c-hachek, j-hachek>.