Serkr is a nord word meaning coat. If anything, Serkr Team's motto should also be in nord instead of latin.
"Coat"? Like, the thing you put on when you go outside? Wow, that's... disappointing...
It's part of the derivation of the compound 'ber''serkr', meaning (maybe) 'bear coat'.
True. To properly become one of them, though, you had to go out, kill and skin an adult bear by yourself. The coat you make with its skin became a sign of strenght and courage.
So, it doesn't sound that disappointing when seen in context. You can say the Serkr Team wears the 'serkr' of UEF frigates.