Angle-resolved photoelectron spectroscopy, supplemented by theoretical calculations has been applied to study the electronic structure of heavy-fermion material CeFePO, a homologue to the Fe-based high-temperature superconductors, and CeFeAs0.7P0.3O, where the applied chemical pressure results in a ferromagnetic order of the 4f moments. A comparative analysis reveals characteristic differences in the Fe-derived band structure for these materials, implying a rather different hybridization of valence electrons to the localized 4f orbitals. In particular, our results suggest that the ferromagnetism of Ce moments in CeFeAs0.7P0.3O is mediated mainly by Fe 3d(xz/yz) orbitals, while the Kondo screening in CeFePO is instead due to a strong interaction of Fe 3d(3z)(-r)(2)(2) orbitals.