  The overlap of galaxy surveys and CMB experiments presents an ideal
opportunity for joint cosmological dataset analyses. In this paper we develop a
halo-model-based method for the first joint analysis combining these two
experiments using 10 correlated two-point functions (10x2pt) derived from
galaxy position, galaxy shear, CMB lensing convergence, and Compton-y fields.
We explore this method using the Vera Rubin Observatory Legacy Survey of Space
and Time (LSST) and the Simons Observatory (SO) as examples. We find such
LSSxCMB joint analyses lead to significant improvement in Figure-of-Merit of
$\Omega_m$ and $S_8$ over the constraints from using LSS-only probes within
$\Lambda$CDM. We identify that the shear-$y$ and $y$-$y$ correlations are the
most valuable additions when tSZ is included. We further identify the dominant
sources of halo model uncertainties in the small-scale modelling, and
investigate the impact of halo self-calibration due to the inclusion of
small-scale tSZ information.
