Now the real problem is that I got lvl 16 after that fight which means I need to pick advanced classes and their descriptions are missing (not a bug but bad design) and I can only really see details of first skill you get from each.
I tried to level up Argenta but could not figure out if Bounty Hunter or Arch Militant is better for burst fire ranged character (it was 2 AM so I didn't have time to study it in detail). And then I need to do same for others..
Arch-militant is extremely strong as long as you use a burst weapon, which Argenta should. While the class pretends to be a melee/range mix you can perfectly use it solely for ranged combats as alternating between single and burst does increase versatilty. Get Wild fire and reckless rush.
Get Cassia to be a tactician, it is great imho, she can get you extra turns and buffs.
I made Pasqal an Assassin which is kind of ass, maybe I don't get the class. Grand Strategist has some pretty strong buffs, that cost nothing (unless you want to make them stronger) to create however those buffs are static on the combat map meaning you hamper your own movement. Vanguard is beefy af but my abelard lacks damage at this point (beginning chapter 3) compared to others.
Idira is a bounty hunter, with shared spoils she can help you get buffs on kills for other characters (costs nothing) but as I use her as a Buffer/debuffer it hardly comes into play.
So my Party is: main Soldier/Achrmilitant you can probably just substitute Agenta, I recommend getting a heavy bolter + Specialisations for her the drusian shop one is not heretic, Navigator/officer/tactician (Cassia great buffs and deals good damage to boot), Abelard Warrior/Vanguard, Merc Officier/Grandstrategist, Idira operative/bounty hunter and Pasqal Operative/Assassin.
So Bounty Hunter is to give buffs to others?
My main is Operative Sniper he usually stands far behind and kills dangerous targets that need to die first. Sounds like doing that while giving buffs to others could work.
My ideal party will be SM companion (do not even know what class he is), Abelard or Henrix as main tank (I guess I can go Vanguard for both if that is tank advanced class), Pasqal melee as secondary tank and damage dealer (not sure what options are for him, I guess advanced class that will give him more damage), Argenta will stay as bolter burst fire specialist (I took that rapid shot and upgrade that removes damage penalty) so I guess I will take ArchMilitant if you say that one is good and finally Cassie as buffer/debuffer.
No, sorry if I made this unclear:
The bounty hunter designates targest that if he kills them he get's buffs depending on the enemies strength.
I think it's Temporary hitpoints for chaff and more and more AP for higher tier enemies.
The thing is that i never use Idira for combat as the buffs are too important. With "shared spoils" a talent, other characters killing these enemies still get half the benefits.
I guess Bounty hunter might work for your main with a sniper due to high single target damage, it's just that both Pasqal and Idira who have these two roles (assassin and Bounty hunter) fail in their respective classes, it was not a good choice, not that i know what better to do with Idira, being a psyker is akin to a class of it's own.
If you have a more agile Pasqal Assassin might actuall work for him, it's melee focused and mobile (getting free movement and bonus damage through so called openings) mine is a toughness melta build though, so i hardly profit from that. I had the same issues figuring out what to with the classes as you.
I'm in chapter 3 now but have not yet encountered the SM companion. I finished basically all exploration and sidecontent (unless bugs hampered me) and I am playing 72 hours now. Jesus.