  Exact diagonalization results for Kondo nanoclusters alloyed with mixed
valence impurities show that tuning the {\it energy spacing}, $\Delta$, drives
the system from the Kondo to the RKKY regime. The interplay of $\Delta$ and
disorder gives rise to a $\Delta$ versus concentration T=0 phase diagram very
rich in structure, where regions with prevailing Kondo or RKKY correlations
alternate with domains of ferromagnetic order. The local Kondo temperatures,
$T_K$, and RKKY interactions depend strongly on the local environment and are
overall {\it enhanced} by disorder, in contrast to the hypothesis of ``Kondo
disorder'' single-impurity models.
