The same root, across a whole language family
These are attested shared morphemes — not coincidences of spelling. Where we are not confident a root is shared, we say nothing and simply list the names.
nike / niki
victory (Greek)
Greek
Agathoniki, Aglaonike, Berenike, Elpiniki, Eunike, Kalliniki, Kleoniki, Nika
victor-
victory (Latin)
Latin, Spanish, Italian, French
Victoria, Victorine, Vittoria, Vittoriana, Vittorina
sig- / sigr-
victory (Germanic)
German, Norse, Icelandic
Sigbjorg, Sigburga, Sigelinde, Sigfrid, Sighild, Sighilde, Sigihild, Sigilinde
Every tradition, side by side
Sanskrit 25
Greek 17
Italian 11
Icelandic 4
Old Germanic 1
Welsh 1
Bengali 1
American 1
Other 1
Buryat 1
Somali 1
Spanish 1
Croatian 1
Punjabi 1
Germanic 1
Frisian 1
Swedish 1
Scandinavian 1
Turkish 1
Coptic 1
Tamil 1
Latin 1
Polish 1