Rocks was pre Roger´s prime. When Sengoku says he was the biggest rival, he is obviously referring to Roger´s condition relatively at that time (i think it was 38 years ago?)
If you want to have an exact copy, you won´t get it. Luffy is not Roger either, Zoro is not exactly Rayleigh and so forth.
But the OP did not as much refer to personality and motivation rather than to external stuff like crew and power.
And BB and Luffy, just like WB and Roger did for theirs, will emerge as the top 2 of this generation on the pirate side