About Christmas Crates

It says on the description that they will not give duplicate items. Taking the smallest crate (250 gold), theoreticaly, does this mean that after opening 19 crates, the next 5 crates will guarantee all five premium ships in the crate? Did I miss or misunderstand something? Are we getting Napoli, Musashi, Enterprise, Leningrad and Sirius for a total of 6k gold?