Thanks Jim. That is what I suspected but I kind of convinced myself that it might work.
Commit Eowyn (as always), commit Thoedred (and do all of the above bringing Eomund into play), commit Eomund.
I thought it was probably stretching it but the 'commit characters to quest' section in the Turn Sequence rules is green, which I though might mean I could use actions as described.
As a new player you will soon notice that when faced with a rule question, the correct answer is always whatever makes it harder for the player. That's the golden rule for LotR.