You do have a bit of backup healing in terms of the paladin, especially to help the out-of-combat load or stand you back up. Abjuration is good at avoiding damage in the first place with their ward. A battlemaster fighter is quite sturdy. You can pull off the healing needed with either. It will be less spells needed for healing with a Life Cleric, so paradoxically the Life cleric will have more slots free for supporting the party in other ways.
You only have one melee front liner, but with Oath of the Ancients my guess is they willing to focus on tanking, not just DPR like an Oath of Vengeance. But still, with only one be prepared to tank. Luckily both get heavy armor.
Since you need to be in the front lines, you'll get hit more. Keeping Concentration won't be as easy, so casting low level spells that you can afford to lose the slot is a bit better.
A good number of the tempest spells take Concentration. Base cleric has a bunch of good concentration spells, tempest expands that list with some good area of effect damage.
Probably your best low level buff will be Bless. No big surprise, but this party has a lot of attack rolls being made. If you want to spend on DPR, Spiritual Weapon and later Spirit Guardians are both good. Tempest has some good AoE damage, but with a wizard that niche does already have coverage.
I think a life cleric, as much as people think it defensive and passive, would better be able to handle tanking and DPR, due to less slots needed for healing so more slots for everything else. The only problem is that without martial weapon proficiency, their Divine Strike to add to weapon damage at 8th is lackluster, doing a point or two less per hit then a character with martial weapons.
One oddity with dwarven clerics - since you don't need STR for heavy armor, and you want a shield/divine focus while tanking, it can often make sense to go for finesse weapons and push your DEX as an attack stat since of all the other goodies DEX brings. I just find it funny that being dwarven enables rapiers and daggers if you want to go that route.
(If you were open to other domains, have you considered Forge from XGtE? They can fill a tanking role even better.)