I've seen lots of exos in the tower with serving jobs like being a post person, cleaning, or being a guide.
I feel like this is the proper role for all exos as I don't think they are very adept in combat.
Whenever I see exos in the crucible I feel like I should destroy their ghost as well so I can dismantle the exo and use their parts to upgrade my weapons.
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I once slipped on a puddle of oil in the crucible. I signaled for the nearest exo to come and wash my robes but as it got closer to me it made the mistake of using its fist of havoc and killing me. Seriously, exos have no place on the battlefield.