  We study the effects of disorder and Coulomb interactions on the physics of
three-dimensional type-I Weyl fermions with tilted and anisotropic dispersions
in a renormalization group approach. To lowest non-trivial loop order we show
that the tendency of the Coulomb interactions to restore the symmetry of the
dispersion in the semimetallic region of the phase diagram dominates the
stabilization of the tilt and anisotropy favored by weak disorder. We argue
that the topology of the renormalization flow of the disorder and Coulomb
couplings is essentially determined by gauge invariance, so that these findings
continue to hold qualitatively at any order in perturbation theory.
