Take it even one step futher ...
If you play evil Fighter, you have Lae'zel, Shadow and Minthara ... you obviously killed Astaripn since he attacked you ... but then your party becpme Fighter, Fighter, Cleric, Cleric. :-/
Something I have been pointing out for a while- It's even worse if you consider that Origins characters are playable. If you are playing, for ex-Asterion, you only get two 'evil' companions as party members+Gale if you side with the goblins. Minthara and Lae'zel are your only romance options, and what's worse-according to the datamined stuff
Shadowheart will try to murder Lae'zel later in the game, and you'll have to pass a hard check (DC 20 iirc) if you want to keep both in your party. Pair that with having to pass another check with Gale, and it's quite possible to end up with less than a full party and with Minthara as your sole romance option.
That's awful.
The game sorely needs more companions and class/role redundancy with companions. In BG I you had a million party members to choose from, practically drowning in choice. BGII had less, but there was still a lot of redundancy, and lots of characters as multiclasses. But in BGII we only get one cleric, one wizard, one rogue, etc, with other popular archetypes not even represented at all-no paladin, no druid, monk, sorcerer, etc.
But to the OP's concern, yeah. There really should be some evil camp followers. The fact that there aren't even one, while good players get tons....is a little concerning for the future IMO. I really hope that Larian has something that they are keeping under wraps for the time being to surprise us with, because so far the evil roleplay experience has been much less developed than the alternatives in BGIII.