I want to focus a bit on the summoning part:
If you want a summoner but don't like to micromanage a lot of characters (which is a bit contradictory in general to be honest because you'll have to steer the summons all the time) you can focus on summons that automatically get controlled by the game AI and are not steerable by the player (most Chanter summons are of the controllable type).
Those autopiloted summons are for example Essential Phantom and Substantial Phantom from Wizard, Many Lives Pass By from Chanter (absolutely awesome with the Death Godlike Troubadour/Priest Kaylon suggested since they will pop up so quickly you will have a small army at all times that automatically attacks), Ancient Brittle Bones skeletons (the ones that emerge if the first skelli does), The Dichotomous Soul from Monk. There may be a lot more, but since I don't use summons of other classes very often (Priest, Druid come to mind) I can't recall which ones are controllable and which not.
Many Lives Pass By skeletons don't count towards the individual char's summon limit. So said Troubadour/Priest can summon a Spiritual Ally and still pop up skeletons while doing so. Which is also great.
There are also other sources than class abilities with allow to put autopiloted summons on the field. Look at Essence Interrupter: if you crit an enemy with it and said enemy dies you will get a summon (that doesn't count towards the summoning limit). Without further enchantment that summon maybe hostile. But with the right enchantment it's always friendly.
Another option is the sabre Grave Calling. It has an enchantment that summons an imp every time you kill a vessel with it. It also works with your own vessels (e.g. Beckoner's Skeletons).
The same thing can be done with the sword Hel Beckoning - just that you have to kill Spirits instead (also works with your own spirits, see Beckoner's Whisps).
If you manage to crit a vessel/a spirit with Essence Interrupter and then kill it with Grave Callings/Hel Beckoning you will get a random friendly summon + an imp! So having a Beckoner in the party and then shooting his skeletons with the bow first and then ki it with Grave Calling gives you 4 summons from one skeleton (1 dead skeleton splits into 2 + imp + random summon) -> all on autopilot.
Looking at Grave Calling more: it has an enchantment named "Chilling Grave" that is mutually exclusive with the imp summons. But the beauty of it is that the Chillfogs it produces count as weapon attacks and thus get all the goodies like dmg bonus from weapon quality, Sneak Attack (if you have) and so on. A Berserker/Beckoner with Grave Callings/Chilling Grave can summon 6 Skeletons with Ancient Brittle Bones -> Frenzy (become confused) -> kill one of his skeletons -> skeleton will split in two and trigger Chillfog -> Chillfog will kill all other skeletons, splitting them and triggering 5 more Chillfogs -> all split skeletons will die from Chillfog and produce 12 more Chillfogs. Meanwhile your skeletons from Many Lives Pass by will run into the Chillfogs all the time and get killed, producing more Chillfogs. It's the Deadfire equivalent of an atomic bomb. If you also use the helmet Heaven's Cacophony with Avenging Storm every Chillfog will also produce lightnings. However, this might fry your graphics card and is the quintessence of a gimmicky build, so...