I can't say that I have theorycrafted a summoning build but I feel like the Paladin may be better than the Cleric.
As far as I know you can't exactly heal minions. For party healing you have access to Warden of Vitality (at level 9) which lets you use your bonus action (for 10 turns) to heal a target for 2-12. You also have access to Lay on Hands.
The Paladin offers 2 auras - Protection (CHA to saves) and Courage (allies can't be Frightened) and the Oathbreaker also offers Aura of Hate (CHA to damage) and has access to Animate Dead.
I am not sure if the Undead attacks count as "weapon attacks" but you also have Crusader's Mantle - concentrate, 10 turns duration, offers 1d4 radiant damage to allies.
TL;DR you have some healing options, you give CHA to saving throws and CHA to damage (and if it works) and 1d4 brilliant damage to allies.
