This work builds upon the recent demonstration of a phononic four-wave mixing pathway mediated by parametric resonance. In such a process, drive tones fd1 and fd2 associated with a specific phonon mode interact such that one of the drive tones also parametrically excites a second mode at a sub-harmonic frequency and such interactions result in a frequency comb fd12±n(fd1−fd2). However, the specific behaviour associated with the case where both drive tones can independently excite the sub-harmonic phonon mode has not been studied or previously described. While it may be plausible to expect the merger of two frequency combs fd12±n(fd1−fd2) and fd22±n(fd1−fd2), this paper indicates that only one of these mechanisms is selected and also shows an interesting transition linked to this process. The frequency transitions from fd12±n(fd1−fd2) to fd22±n(fd1−fd2) holds promise for computing applications.