  We present the discovery and validation of two TESS exoplanets orbiting
nearby M dwarfs: TOI-2084b, and TOI-4184b. We characterized the host stars by
combining spectra from Shane/Kast and Magellan/FIRE, SED (Spectral Energy
Distribution) analysis, and stellar evolutionary models. In addition, we used
Gemini-South/Zorro & -North/Alopeke high-resolution imaging, archival science
images, and statistical validation packages to support the planetary
interpretation. We performed a global analysis of multi-colour photometric data
from TESS and ground-based facilities in order to derive the stellar and
planetary physical parameters for each system. We find that TOI-2084b and
TOI-4184b are sub-Neptune-sized planets with radii of Rp = 2.47 +/- 0.13R_Earth
and Rp = 2.43 +/- 0.21R_Earth, respectively. TOI-2084b completes an orbit
around its host star every 6.08 days, has an equilibrium temperature of T_eq =
527 +/- 8K and an irradiation of S_p = 12.8 +/- 0.8 S_Earth. Its host star is a
dwarf of spectral M2.0 +/- 0.5 at a distance of 114pc with an effective
temperature of T_eff = 3550 +/- 50 K, and has a wide, co-moving M8 companion at
a projected separation of 1400 au. TOI-4184b orbits around an M5.0 +/- 0.5 type
dwarf star (Kmag = 11.87) each 4.9 days, and has an equilibrium temperature of
T_eq = 412 +/- 8 K and an irradiation of S_p = 4.8 +/- 0.4 S_Earth. TOI-4184 is
a metal poor star ([Fe/H] = -0.27 +/- 0.09 dex) at a distance of 69 pc with an
effective temperature of T_eff = 3225 +/- 75 K. Both planets are located at the
edge of the sub-Jovian desert in the radius-period plane. The combination of
the small size and the large infrared brightness of their host stars make these
new planets promising targets for future atmospheric exploration with JWST.
