Personally I think Argus and Archer are too close for siblings names so therefore I wouldn't use it for that very reason alone, sorry.

I prefer Jobe as a first name instead and that is still very unusual.

Love love love Harper.

Some other alternative for boys names that are a bit unusual are:

Mason
Jonas
Jonah
Reef
Zane
Taine
Tana
Benson
Eden
Kailan
Callan.

Good luck!