“…Numerical investigations of the excited spectra of certain two-level one-and two-boson systems [e.g., exciton [3,4] and E⊗e Jahn-Teller (JT) model [5]] show the existence of level avoidings and related highly excited "exotic" (localized) states. Signatures of chaos in twolevel boson systems remain objects of interest since the early studies by Hamiltonian methods [6,7,8,9,10,11]. Later on statistical methods based on the random matrix theory -e.g., level spacing and level curvature probability distributions -were applied mostly for one-phononmode models.…”