Frodi "the peaceful" Dansson, King of Denmark - Title

During a quick clean up i was going to remove the title "King of Denmark" owing as to how Frodi lived about 600(?) years before the unification of Denmark but i hesitated not knowing what to change it to. Reading his About suggests "King of the Danes" but I have no idea if that is anymore accurate?

Danish king. He was a dane and a king but not king of all danes.

Not directly relevant but is "Dag" a male or female name? Can it be used by both?

Cleaning up "surnames" around Dag "the Wise", King of Uppsala but noticed that his mother is also named Dag.
Could be slight confusion by new user or inexperienced researcher or just me :)

The MP version of Dag Dyggvasson is here:

Dag "the Wise", King of Uppsala

His mother is an NN - the saga source doesn't mention her. Likely the entry of Dag as her name was an user error.

Thanks Harald