I have to go back to PD9
If every pleasure were condensed and were present at the same time and in the whole of one’s nature or its primary parts, then the pleasures would never differ from one another.
Εἰ κατεπυκνοῦτο πᾶσα ἡδονὴ, καὶ χρόνῳ καὶ περὶ ὅλον τὸ ἄθροισμα ὑπῆρχεν ἢ τὰ κυριώτατα μέρη τῆς φύσεως, οὐκ ἄν ποτε διέφερον ἀλλήλων αἱ ἡδοναί.
But pleasures can't be condensed and present at the same time, therefore they differ in time/duration and what parts are affected.
However, every pleasure is the same in that they are pleasurable. That might be the thing that's getting conflated.
That said, IF one is filled entirely with pleasure, different pleasures provide variety but not more pleasure. So, the fact that they differ in variety also means they differ in duration and parts affected.