I got my rogue to take out the 2 archers first because I find them the most annoying.
Since you went with the knight I assume you have ram? I use the first turn to buff/save AP for melee so the ranged enemies have to walk to get to me. Use ram and crushing fist next turn to incapacitate the mages and others that you can get along the way
If Jahan has summons, summon something. Otherwise let him stay in the back for support damage and healing when necessary.
Prioritize melee enemies last because they are the least of your threats. But in a pinch, if you have cure wound use them on the zombies as it is an instant kill (e.g. Use it on the fortified zombie since cure wound is not affected by armour)
I think your rogue can get charming touch at this point so you can use to even out your numbers too in the beginning
Also, have you done the lighthouse yet?
