1.) Start a new game in BG:EE on Legacy of Bhaal mode. Proceed to the house in the south of Candleekeep with Obe the illusionist. Quicksave before you enter.
2.) Enter the house. The temporary companions Arkanis, Canderous, Osprey, Mordaine, and Deder should have the appropriate levels and corresponding hp.
3.) Load the quicksave you made prior to entering the house. Enter the house again. Arkanis, Canderous, Osprey, Mordaine, and Deder will now all be ~Level 14 and have well over 100 hp each.
I submitted a bug report on this, but I was wondering if anyone knew any fixes or workarounds for it. At first I thought it might be a mod issue, but I reinstalled the game and started a new unmodded game and am still having the same problem.