Concluding from over 25 years of own continuous practice in meditation and yoga with many experiences in dhyana and samadhi I´d say that the differentiation of the states of dhyana and samadhi you talk about is a highly overestimated topic throughout the "yoga scene". While it´s true that Patanjali gives emphatic importance to these states in his theoretic foundation of yoga - especially in the third chapter of "Yoga darshana" - it is true as well, that in practice the differences between these states do not follow this clear distinction.

Of course you are free to try to realize a clear concept and structure of "states" of your mind. I think this can only be fulfilled in a way which I consider to be a bit violent, because in reality, "mind" is always fluctuating between instable states - so what´s the point?

For me it has proven to be very fruitful simply to continue meditation without trying to intellectually identify meditative "events" with theoretic concepts and vice versa. Sometimes it happened that I suddenly have heavy insights ("Oh - THIS was meant"), but I never tried to enforce this.

Roger