  Motivated by the realization of spin-valley Hubbard on triangular moir\'e
superlattice in ABC trilayer graphene aligned with hexagon boron nitride (hBN)
and possibly also in twisted transition metal dichalcogenide homobilayers, we
study possible Mott insulating phases and pseudogap metals based on symmetry
constraint and parton mean field theories. First we show that Luttinger
constraint allows two distinct symmetric and featureless Fermi liquids when
there is an inter-valley Hund's term breaking $SU(4)$ spin rotation.
Especially, there exists a symmetric and featureless "pseudogap metal" with
small Fermi surfaces. Then we suggest to search for such an unconventional
metallic state by doping the Mott insulator at $\nu_T=2$. For this purpose, we
study the $\nu_T=2$ Mott insulator using $SO(6)$ Schwinger boson or Schwinger
fermion parton. At the $SU(4)$ symmetric point, we find two symmetric $Z_2$
spin liquids. With a large anti inter-valley Hund's term, a featureless Mott
insulator is natural. Next we show that doping the featureless Mott insulator
or a $Z_2$ spin liquid can lead to featureless or orthogonal "pseudogap metal"
with small Fermi surfaces proportional to the doping. Besides, we also provide
one scenario for the evolution from "pseudogap metal" to the conventional Fermi
liquid through an intermediate exotic "deconfined metal" phase. Last, we give
brief comments on the possibility of $U(1)$ spinon fermi surface state or $Z_4$
spin liquid at $\nu_T=1$.
