Here are a few suggestions, any one of them would suffice.
1) Adding in a new ability, call it "First-Aid" or "Battle Med", it would functionally be like a Second Wind. "First-Aid" is a common ability in many FF games, usually for basic jobs.
http://finalfantasy.wikia.com/wiki/F..._%28ability%29
2) When Hot Shot is used with a stack of Ammunition, the MCH is healed by 100% of the damage dealt by the Hot Shot.
3) Reassemble gains this property in addition to ensuring critical damage to the next weapon skill: Damage dealt will be absorbed as HP, up to 10% of maximum HP.
4) Ability called Transfusion: Sacrifices your turret and disables Deploy for 30 seconds. An AoE heal, equal to the Turret's remaining HP will be split amongst party members in range and heal up to 10% of their Max HP.
http://finalfantasy.wikia.com/wiki/S..._%28ability%29