I come upon an adventurer.
I'm on the cloth map if that matters, not sure if the 3D view shows more characters when there's a group.
I see an adventurer and talk to her (right click with my sovereign), she proposes 86 gildar and will join me.
I pay.
I then get a message asking me whether I cancel/auto-battle/fight her.
I think it's going to crash if I do anything but cancel, and I don't want to fight anyway, so I cancel.
I then see some unit moving into my stack and the adventurer remains where she is, and I get a message from here saying city XXX is ripe for the taking.
Of course, the city is emmpty, I just went out in order to buy her.
Now I look at my stack and realise that instead of buying a loremaster female wandering champion, I got a level 2 male adventurer who had apparently been hiding beneath her robes or something. If I talk to the girl again, her price is only 63 gildar and she will indeed join me.
If the adventurers are stacked, they should either be bought all together and show the right price, or not be buyable, or each of them should be.