  We discuss a theory of flavour in which Higgs Yukawa couplings are related to
those of the new scalar triplet leptoquark and/or $Z'$ responsible for
$R_{K^{(*)}}$, with all couplings arising effectively from mixing with a
vector-like fourth family, whose mass may be anywhere from the Planck scale to
the electroweak scale for the leptoquarks explanation, but is pinned down to
the TeV scale if the $Z'$ exchange plays a role. However, in this particular
model, only leptoquark exchange can contribute significantly to $R_{K^{(*)}}$,
since $Z'$ exchange is too constrained from $B_s$ mixing and $\tau \rightarrow
3 \mu$, although other Higgs Yukawa matrix structures may allow it.
