  Leptoquarks with masses between 2 TeV and 50 TeV are commonly invoked to
explain deviations between data and Standard-Model (SM) predictions of several
observables in the decays $b\to c\tau \bar\nu$ and $b\to s \ell^+\ell^-$ with
$\ell=e,\mu$. While Leptoquarks appear in theories unifying quarks and leptons,
the corresponding unification scale $M_{QLU}$ is typically many orders of
magnitude above this mass range. We study the case that the mass gap between
the electroweak scale and $M_{QLU}$ is only populated by scalar Leptoquarks and
SM particles, restricting ourselves to scenarios addressing the mentioned
flavour anomalies, and determine the renormalisation-group evolution of
Leptoquark couplings to fermions below $M_{QLU}$. In the most general case, we
consider three SU(2) triplet Leptoquarks $S_3^\ell$, $\ell=e,\mu,\tau$, which
couple quark doublets to the lepton doublet $(\nu_\ell,\ell^-)$ to address the
$b\to s \ell^+\ell^-$ anomalies. In this case, we find a scenario in which the
Leptoquark couplings to electrons and muons are driven to the same infrared
fixed point, so that lepton flavour universality emerges dynamically. However,
the corresponding fixed point for the couplings to taus is necessarily opposite
in sign, leading to a unique signature in $b \to s\tau^+\tau^-$. For $b\to
c\tau \bar\nu$ we complement these with either an SU(2) singlet $S_1^\tau$ or
doublet $R_2^\tau$ and study further the cases that also these Leptoquarks come
in three replicas. The fixed point solutions for the $S_3^\ell$ couplings
explain the $b\to s \ell^+\ell^-$ data for $S_3^{e,\mu}$ masses around 10 TeV.
$b\to c\tau \bar\nu$ data can only be fully explained by couplings exceeding
their fixed-point values and evolving into Landau poles at high energies, so
that one can place an upper bound on $M_{QLU}$ between $10^{8}$ and $10^{11}$
GeV.
