I think I know what is happening here, I just came back to EQ and it was frustrating me. Now my only big problem is occasionally pull stalls where my puller stops in the middle of a pull and stays there til he gets killed by a roamer :P
1: Possibly increase your campsize on your sk (not too big), and keep all your other toons within that radius (use /mapf castradius ## .. .with ## equal to your campradius, if you want to see how big it will be).Start kissassist and set them to returntocamp so they stay in that area. As an extra option set up your other characters not only insidet the radius of the SK's campradius, but with their own campradius set SMALLER than the tanks, to help keep them within his range of assistance. My tank has a campradius of 40, the other characters are 15-30, slightly differed so if they end combat still in the camp they dont all run back to the exact same spot EVERY single time (which is pretty obvious to watchers)
2: Increase MeleeDistance on the SK. Preferably slightly bigger than your campradius. My tanks camp radius is 40, and his meleedistance is 75. This determines how close a mob on the hatelist has to be for the character to attack. If its too short, your SK(or any other character) will happily sit there and watch an add eat your healer. Set other melee dps slightly larger than your tanks melee distance (in this case, my tank is set to 75, and they're set to 85 to account for range differences depending on which direction mobs come from). This number can and should change depending on the camp you're doing, but these numbers are working well for ME. Setting up your meleedistance like this accomplishes a couple things, A: Your tank will try to engage a little further away from the healers/casters, and B: it should prevent/help prevent situations where the tank engages but your other melee dps sits around not helping.
3: You can also set meleedistance on casters (but leave meleeon=0) to a really high number, in line with their spell range. I'm not 100% sure but I think this has to do with actual assist range not just melee, so if mobs run away and for whatever reason your bots dont follow them the casters will keep nuking. I'm not entirely sure about this because its been years, but it wont hurt anything if you set it up to 200 on your nukers anyway as you aren't going to have them run up and melee (I hope)