You can because you have some other skills to support Aegis as Pally.
Here are Shield Paladin builds:
Physical Aegis / Kalastor / RF
Chaos Aegis (very low cooldown)
Pierce Spam Aegis (no cooldown)
Elemental Aegis / Kalastor
Elemental Runes
Fire Aegis
Fire Kalastor / Guardians
Fire RF
Physical RF
Elemental Aegis / Vire’s Might
Fire Judgment / VM
Chaos Aegis / FoI