Kilts are Celtic Cultural thats why their name also , but this game is more Viking oriented so I guess no Kilts ...
1) The naming of kilts is not etymologically related to Celt at all; it's actually from a Scandinavian word meaning "to tuck." The origin of Celt is uncertain but is first attested in Greek "Keltoi"; possibly related to a word meaning "to cut."
2) The ancient Celts wore trews (trousers) among the lower classes and robes among the upper classes.
3) Kilts are not specifically Celtic per se. The Egyptains wore kilts when the Celtic culture had not yet developed from the Halstatt culture or even the broader Indo-European culture. Many other Europeans wore kilts. The Norse wore kilts.
4) There's a strong Celtic influence in the Nords anyway. Yes, the bulk of Nord inspiration comes from the Germanic Anglo-Saxons and Norse, but there's a decided Celtic influence too (a little bit of Gaulish, but mostly Brythonic).