You have to be careful with baby name books and sites that are more of a baby name book site. They tend to try and beautify names, or arrange them in a way they don't have to give the full explanation.
Seaphine comes from the Hebrew word seraphim, which means 'firey ones', but was a type of angel. Therefor it is easier for a baby book to say 'firey angels' then to give the word for word derived meaning.
For example, the name Cameron, now used as a given name, but oringally only a surname, is gaelic from 'crooked nose' but in a baby name book I have, it says Cameron is gaelic of 'individuality'.
Additionaly, many sites say Vanessa means butterfly, when the name was actually created, and has no meaning. Later a genus of butterfly was named after a character in a novel Vanessa. And so you can choose to name your child after a butterfly, as much as someone could name their child Monarch, but that doesn't make monarch mean butterfly, a monarch is still a ruling regent of a monarchy system.
So it likely does mean 'firey ones', their may be descrepancy on the translation, but the descrepancy would not be between 'ones' and 'angels', that's just an authors opinion and bias.