they could of been named after halfgods offspring of jupiter and his mistresses :D then the moons would be the kids of jupiter :D
google says this:
Jupiter
Consort Juno
Children Mars, Vulcan, Bellona, Juventas
Parents Saturn and Ops
Siblings Roman tradition: Juno, Ceres, Vesta Greco-Roman: Pluto and Neptune
pehraps they were taken already for some other celestial bodies. idk too much about that.
super cool for the dude though that his names got picked :D must be feeling like a champ :D