First Run Question re: Max XP gain before Jaheira-Khalid?

[Eadwyn G8Keeper]

I am planning to recruit Imoen, Jaheira-Khalid, Ajantis and Kivan in Early Game with my PC as a Fighter/Mage.
My RPG story involves dismissing Xsar-Montaron after the Tarnesh encounter. Taking Xsar to 2nd floor for 'a little talk' while leaving Montaron near Jaheira-Khalid. Thus when Montaron mouths off subsequently I plan to Charm Khalid and Fight Montaron then probably have it out with Xsar also.
I am fairly sure that this will incur no Rep loss. [Neutral Good Alignment].

My question is whether this will garner XP enough to make Ajantis or Kivan Level 3 when recruited. Which I want to avoid.

Note: Planning to do Unshey's Ogre quest after recruiting Jaheira-Khalid but before Ajantis.

Is there a Standard Rule about early XP gain for Charname-Imoen that is more precise than 'Minimal'

Thanks in advance for all comments. Respects.

[Claudius]

You could save hairpulling by just assigning adjantis and kivan the HP they would have gotten if you had picked them up early. Just a thought. There must be a BG1 version of shadowkeeper.