Multiple orbits permitted
The Ioun stones (DMG, 176) have no limitations on more than one being used, so you can absolutely do that!
But they do require attunement, so unless you can attune to more than 3 items, you can only have 3 going at any given time (and no other magic items.)
Just remember that they are somewhat free floating and other creatures can target them:
Thereafter, another creature must use an action to grasp or net the stone to separate it from you, either by making a successful attack roll against AC 24 or a successful DC 24 Dexterity (Acrobatics) check.