Imperial custom does not distinguish maiden names, married names, hyphenated names etc. in a very systematic way. People are free from the age of eighteen to choose whatever names they like: very often they choose something dramatic or flamboyant at that age. As frequent name-changes are socially (but not officially) frowned upon, they tend to feel stuck with that name after they have tired of it, and are inclined to change it to something subtler only after a life event that their peers will recognise: perhaps as early as commissioning/permanent appointment with the Imperial Service, very often becoming affianced, and also frequently when deciding to have children, but perhaps as trivial as being transferred to a different station where they will acquire a new social circle. Upon affiancing, it is fairly common for both members of a couple to change their name to the same. The custom is not universal, but it is more common than the woman changing her name to match her man's, or any systematic combination.
Although one is free to assume any name officially speaking, it is considered in very bad taste to adopt names that might suggest a connection to certain families when one does not actually have one. Among these names are: Ath, Eichberger, Kobayashi, McArthur, Medforth-Mills, Minamoto….
Of course, there are a large number of colonial recruits in the Imperial Service who stick with names that they acquired under the arrangements of their own societies.