My personal advice is to keep things natural, go where you want (and can without getting slaughtered) talk to everyone, have those who can join you join, and if they decide you are not to their taste, let them leave (or kill them :P). This is one of the few rare examples of an RPG where you are really free to do as you please outside of the main story (and even have quite some freedom there too). Don't get caught up in doing everything "perfectly" or you will never finish it.

If you don't mind spoilers, read this: https://arcanum.fandom.com/wiki/Followers

There are also a few metagaming tricks (tricks, not cheats, mind you) that you can use to keep a disgruntled follower in the party, but I doubt you want to do something like that.

You can have more followers if you up your Charisma (CH), and take enough ranks in Persuasion to be able to buy expertise. The game limits you to 6 though (not counting free followers like Dog, or temporary ones who join you for a quest).

Followers who don't mind if you're evil include Geoffrey Tallerond-Ashe, Vollinger, Dante, Torian Kel, and Z'an Al'urin. (Torian's a bit of an odd duck: as the game's only True Neutral NPC, he doesn't like extreme evil any more than he likes extreme good.) Virgil will also follow you regardless, at least for the bulk of the game.

One further protip: if you get your CH up to 20, with or without Persuasion mastery, none of your followers will leave you unless you dismiss them. This is one of the few ways to get mortal enemies (such as Geoffrey and Perriman Smythe, or Z'an and Raven) to be willing to travel together.

Actually that is sort of true with high charisma. Followers can still turn against you if you do stuff they don't like like killing townspeople when they are there. The loyalty in the game is very wonky, sometimes they drop in loyalty for things, and sometimes doing the exact same thing won't drop their loyalty. Then i've played through the game where i've had their loyalties for some reason jump up to like 200-250 where other games they just stayed "loved" at 100ish. Very unlogical system.

Maybe with 20 charisma and max persuasion they won't leave, but ive played through many times with 20 charisma and max persuade characters where their loyalty will drop when you do things they don't like, though it doesn't happen often. And if your not paying attention they will turn against you and fight you. Your main party memembers you can buy items to raise loyalty before that happens, but you can't do such things with other characters, and if they turn hostile, its a reload if you don't want to lose them, or drop them, do your dirty deeds, and bring them back.

So be evil and keep who you like. Read up on the items you can buy cheap in the stores that you can give to low loyalty followers to raise them back up to neutral status. This should help out a bit. Higher charisma and persuade help to keep their loyalty high and not drop, but it still might happen infrequently so just keep an eye out every so often. They might complain when they are nearby and you do bad things, but that won't mean their loyalty will drop or that they will turn against you. they MIGHT, but when or when they don't do such things, seems a toss up to me based on my playthroughs.

I've had my mage/leader with max beauty, charisma, persuade, bla bla still have trouble with high loyalty, and i've had my all-skills character without very high beauty, with 4 magic affinity, look about and followers were 200+ love loyalty in the early game. Kinda wonky.

Sogg doesn't turn suspicious if a character is evil.

For most companions, their reaction is affected by :
-Beauty,
-items that improve your reaction/beauty (smoking jacket, elegant dress, jewel of Hebe),
-some blessings (Arbalah, Brigitte, master healer -not a blessing but it does boost your reaction modifier),
-completing quests related to their origins when available (Sebastian, Loghaire, Raven, ...),
-hiting them (intentionally or not) in combat lowers their reaction,
-if your actions are in their alignment range or not (this range is different for each follower).
These are the major modifiers and there are also some unique modifiers such as dialog options, advancing in the main quest with them, ...
N.B. : there are 3 exceptions : Dante, dog and Waromon. These 3 companions are unaffected by beauty modifier. Blessings and items do not improve their reaction (with the exception of master healer which can affect them too).

When a companion reaction drops as low as dislike, you can usually feed them with an item to restore it. For Sogg, it's a bottle of wine. There must be a typo. Dante definitely minds if you're evil.

More infos on the available evil companions :
- Geoffrey Tallerond-Ashe, lvl 12 mage, Ashbury : must be evil and complete his quest to hire him (Perriman will not party with Geoffrey).
- Vollinger, lvl 15 gunslinger, Dernholm : no requirement, can even follow a good-aligned character.
- Torian Kel, lvl 20 pure melee, Ancient temple : must be evil and complete his quest to hire him (Magnus will not party with Torian).
- Z'an Al'urin, lvl 29 mage, T'sen-Ang : must be evil (Raven will not party with Z'an).
- Tollo Underhill, lvl 30 thief, Dernholm pits : must be very evil and have joined the dark elves.
Aptitude : 2 tech followers (Vollinger, Tollo), 2 mage followers (Geoffrey, Z'an) and 1 with no TA/MA (Torian).

Note that there is no evil support/healer so you may have to consider to put points in Necro Good (if mage) or Herbology (if technologist).

As mentioned, CH 20 prevents any follower to leave you while mastery of persuasion negates the alignment requirements and allows to hire anyone (except Jayna).
Example : to get both Raven and Z'an with you, you need mastery of persuasion (to dismiss the alignment requirement) and CH 20 (to prevent them from leaving the party).

My suggestion as to who to get : 1 follower involved in the main quest (Virgil, Z'an), 1 porter (Sogg, Torian), anyone else you want or can provide useful skills (Vollinger has tech disciplines, Tollo can picklock and disarm traps, Z'an can summon earth elementals).

If there's one thing I can add to this topic - if you're playing the full evil route, you won't be able to recruit Raven, even with full persuasion. The markoff point will be when you butcher the residents of Stillwater. Upon returning to Qintarra, Raven will accuse you of making a deal with the Dark Elves.

That being said, I have not tried killing Min Gorad after butchering the denizens of Stillwater, then approaching Raven agai (and this is assuming I can still contact Kan Hua after picking up Raven). If someone has tried this, please confirm it. But so far, Raven seems to be the only character "stuck" to the main path of the game.

~

Also, and if you have Torian in your party - ditch him before entering the void. You will find a similar character in the Bane of Kree, whom you will meet in the Void. I am mentioning this because, at the very end, Torian will betray you, even on full persuasion. It became a bit frustrating that I settled for leaving him back in Arcanum and getting the Bane of Kree to take his place.