  The spatial distribution of Milky Way (MW) subhaloes provides an important
set of observables for testing cosmological models. These include the radial
distribution of luminous satellites, planar configurations, and the abundance
of dark subhaloes whose existence or absence is key to distinguishing amongst
dark matter models. We use the COCO $N$-body simulations of cold dark matter
(CDM) and 3.3keV thermal relic warm dark matter (WDM) to predict the satellite
spatial distribution in the limit that the impact of baryonic physics is
minimal. We demonstrate that the radial distributions of CDM and 3.3keV-WDM
luminous satellites are identical if the minimum pre-infall halo mass to form a
galaxy is $>10^{8.5}\mathrm{M}_{\odot}$. The distribution of dark subhaloes is
significantly more concentrated in WDM due to the absence of low mass, recently
accreted substructures that typically inhabit the outer parts of a MW halo in
CDM. We show that subhaloes of mass $[10^{7},10^{8}]\mathrm{M}_{\odot}$ and
within 30kpc of the centre are the stripped remnants of larger haloes in both
models. Therefore their abundance in WDM is $3\times$ higher than one would
anticipate from the overall WDM subhalo population. We estimate that
differences between CDM and WDM concentration-mass relations can be probed for
subhalo-stream impact parameters $<2$kpc. Finally, we find that the impact of
WDM on planes of satellites is likely negligible. Comprehensive comparisons
with observations will require further work with high resolution,
self-consistent hydrodynamical simulations.
