We've got one spell with Ris, so it's either Grease or Sleep, not both. I vote Grease as Sleep only affects 4HD total (max 4 orcs) while the grease affects all who try to get through it.
Ris and I both have some caltrops, which can endanger a 5ft square each (I believe I bought another "dose" or bag, so we can do three squares total. I am emailing DEW because back on 9/11 I indicated intention to buy some things that he has not said are in my possession (Tanglefoot Bags & Acid Flasks.)
I think generally it will be Tom's suggested tactics (grease, then caltrops after the grease for those that get through it) with Halee holding an action to attempting Intimidate on a single orc that might get through.
I think Thomas' Dazzling Display is best used on the other group, the shaken condition affects their to hit, but not their AC, so it does not make those that fall or are slowed any easier to hit, and wastes whatever penalty they would have on not-combat.
I think those rounds of shaken would be best used on the other group who are going toe to toe with our melee guys with no ranged weapons or a barrier or grease/caltrops slowing them down.
I think Cord, Ansic and Uthalin should all rush the smaller group to pin them in the choke point so they cannot spread out.
Thomas get to a point where he can Dazzling Display that group.
Halee dialogs… "You say Magor is strongest, bestest? He ran away like the sniveling, ankle-biting, goblin-loving cowardly pup he is! You saw it. Look at him, he doesn't deserve your loyalty, he's a drooling pup! If Magor was worth ANYTHING he would be right up front leading you, look how he shields himself with all of you like a coward! He wants you to die, does not care if you die, as long as HE is safe. There are many more of you than him, make him prove he's the bestest and strongest, make him come out front like a REAL LEADER should."
(Ris translate if he can…)
We'll check their reaction at that point. Ris ready to cast grease if they charge.
Set an action for all the ranged weapon guys to pepper Magor if they do push him to the front, try to drop him right away and force a morale check on the orcs.
Hopefully they fail and flounder, if they charge, Ris cast the grease, Halee with caltrops, then intimidate any that get through, ranged weapons, etc.
This is exactly what Echoco is suggesting also… fighting the backdoor group while talking with the bigger group.
All of that is OPINION only, not ordering a concrete set of actions… players make your suggestions for better options, please.