In 2013 the IceCube collaboration announced the discovery of a cosmic neutrino flux up to PeV energies, validating neutrino astronomy as the next promising observational technique to explore the high-energy Universe. The neutrino community is moving forward with the construction of new facilities to enhance the detection of these elusive particles at higher energies (up to and beyond EeV) and to increase the statistics at the high-energy end of the IceCube neutrino flux. Future large volume neutrino detectors, using both the radio Askaryan and the optical Cherenkov signal, will open the possibility of hybrid detection of neutrino interactions within the polar ice. In this contribution we present a first calculation of the expected number of events for a simplified geometry of one radio station located at 200 m depth in the vicinity of a $\sim$ 10 km$^3$ in-ice Cherenkov detector, similar to the planned IceCube-Gen2 neutrino observatory. Preliminary simulations show that a total event rate of $\sim 1$ event/year is achievable for a 10-stations array assuming that the Askaryan radio detectors can lower their energy threshold down to $\sim$ PeV energies. Such a possibility is currently under study for the future radio extension foreseen as one of the surface components of IceCube-Gen2.