While I can partly agree with your statement, please consider the fact that we Poles up to 16th century were calling ourselves Vandals and other nations called us by this name.
Polish rulers since Duke Mieszko I were often titled as dux vandalorum (duke of Vandals).
Bolesław the Brave wasnt the first king of Poland but even according to German sources 16th king of Vandals.
During first 500+ years of our history we called ourselves Vandals. In the begining of XVI century we started to call ourselves Sarmatians. In the 19th century we started to call ourselves Polish people. Who knows what name will we take next
Inscription on the western slab of the column of Sigismundus III Vasa: 44th king of our kingdom.
If Sigismundus was really the 44th king then indeed Bolesław Chrobry, who is considered the first king of Poland but who had no idea about such kingdom and titled himself Rex Sclavorum, Gothorum sive Polonorum (king of Slavs, Goths and Polans) was the 16th.
His title also raises question who were Poles. According to his titulature Polans were neither Slavs nor Goths. So maybe Sarmatians? Or someone else?
The fact that Mieszko was 15th king and Bolesław was 16th, means that Church has destroyed our history and condemned it for being forgotten. Most likely the people of Church did hate Vandals for two reasons. First was that they have plundered Rome and the second was that they were Arians (most likely converted into Arian christianity on their way to Rome). It is somthing that we know for sure because this fact was recorded in history. The kingdom of Vandals and Sarmatians in northern Africa was also Arian and not catholic. Arianism was a christian heresy started by bishop Arius which became very popular among barbarian tribes outside both Roman Empires.