Homing, synchronizing and distinguishing sequences (HSs, SSs, and DSs) are used in FSM (Finite State Machine) based testing for state identification and can significantly reduce the size of a returned test suite with guaranteed fault coverage. However, such preset sequences not always exist for nondeterministic FSMs and are rather long when existing. Adaptive HSs, SSs and DSs are known to exist more often and be much shorter that makes them attractive for deriving test suites and adaptive checking sequences. As nowadays, a number of specifications are represented by nondeterministic FSMs, the deeper study of such sequences, their derivation strategies, and related complexity estimations/reductions is in great demand. In this paper, we evaluate the complexity of deriving adaptive HSs and SSs for noninitialized FSMs, the complexity of deriving DSs for noninitialized merging-free FSMs.