You don't need summons to save Gondians. Just bring Gale with Evocation school so his aoe doesn't hit allies, and send him to the wing where the two Gondians and Omeluum are. Send Shadowheart with him to make sure no Gondians die. For the other two tunnels you only need a single character, and all you gotta do is kill 2 Sahaguins on each path, which should be trivial with Martial classes.
Then for rescuing Duke Ravenguard if you broke Wyll's Pact, just throw an invisibility potion at him before he steps out of the cell. Mizora will appear after he comes out of the cell and summon the explosive spiders, but the explosive spiders will just sit there and do nothing since they can't see the Duke, and you can just have him dash to safety alongside the other Gondians.
For the last wing, with the two sahagin and the two Gondian cages, throw speed potions at each group. It will speed them up massively. Remember to not release Gondians while Sahagins are still alive.
Remember to rescue Omeluum last because he has a spell to teleport the character that rescued him to the submarine alongside him. Park a companion right besides the ladder to the entry of the submarine and you can wait for all the Gondians to make it and even when the turns expire, if everyone got in your last companion by the ladder gets through.
Use Alchemical Fire to free Gondians off nets if you messed up. The Alchemical fire will burn the nets as a grenade but only does like 3-4 damage, so the Gondians are pretty safe to escape and heal up. You can also use Shadowheart's Sanctuary spell to protect low health Gondians.
For the Steelwatch Foundry, it's much harder because you have to reload until the AI stops doing suicidal things. You will need big AOE from Gale with Evocation school so the aoe does not hit your allies again. Shadowheart should have the gloves that apply 50% physical damage resist on targets she heals for 2 turns as well as Arcane Tower Staff for buffed up Bless and the ring that gives Bless on heals. One Mass Healing Word will buff up your allies with Bless and physical damage resistance.
Get the staff from Lorooakan's Tower or the Spellmight staff that gives arcane battery so you can use the passive to make Gale not use up a spell slot once. You use this on chain lightning and fry the group to the north with the steel watcher. Use a speed pot, cast another chain lightning. Then just use Ice Storms on enemy groups, it will make them prone and do decen aoe damage while the rest of your team mops up.
Number one priority is deactivating the death detonation crystals the commanders drop. You'll see these little purple floating crystals that are either spawned by the commanders or pop up when they die. If you don't deactivate those with a character before their turn, they mass detonate and instakill the gnomes. Keep aoe healing with Shadowheart and hope the gnomes are not idiots and drop a grease bottle besides a fire barrel and cast a fire spell, it happened to me right as I was about to save all of them and only a steel watcher was left.
AI for allies in this game is incredibly stupid.
