Slow light plays an outstanding role in a wide variety of optical applications, from quantum information to optical processing. While slow optical guiding in photonic crystal waveguides is typically based on Bragg band gaps occurring in non-resonant photonic crystals, here we explore the possibility to leverage the hybridization photonic band gaps of resonant photonic crystals to induce a different form of slow light guiding. We study a line-defect waveguide in a periodic structure composed of high-permittivity resonant dielectric objects and exploit the different guiding mechanisms associated with the hybridization band gap to induce slow light in the resonant phase of the crystal. We demonstrate quantitatively that this method can, in principle, produce high group indices over large bandwidths with potential values of group-index bandwidth products up to 0.67.