The authors disprove conjectures on simultaneous stabilizability conditions by showing that, unlike the case of two plants, the existence of a simultaneous stabilizing controller for more than two plants is not guaranteed by the existence of a controller such that the closed loops have no real unstable poles. An example of a plant which has the even interlacing property but which is not stabilizable by a bistable controller is presented.
Blondel, V., Gevers, M., Mortini, R., & Rupp, R. (1992). Stabilizable by a stable and by an inverse stable but not by a stable and inverse stable. Proceedings of the 31st IEEE Conference on Decision and Control (Cat.No.92CH3229-2), Vol. 1, p. 832-3. https://hdl.handle.net/2078.5/230452