Okay, I considered a couple plans. A relatively safe one, one that was pretty dangerous, and then this one:
Sharne to 13-10, stab Rider B (autohit), gets countered and possibly hit. 6 damage, bringing Rider B to 9 HP.
Esther to 12-8, Worm Rider B to death, get sword as reward. 95ish chance to hit. (11 damage)
Farra to 13-9, shoot Rider D. 95 chance to hit. 5 damage, bringing Rider D to 8.
Roux autokill Rider D, get sword, don't canto. (9 damage)
Brock to 14-8, hatchet Rider C. 98 chance to hit. 10 damage, bringing Rider C to 3.
Martyn to 17-9, knife Rider C, 81 chance to hit and kill, get lance. (3 damage)
If Martyn hits:
Liam to 15-9, vuln Roux, canto back to 15-8.
Sam bard Brock and Esther.
Brock to 15-7, hatchet Rider A, 98 chance to kill and get lance. (10 damage)
Esther to 14-8, swap Roux to using her new sword.
Kaldach to 17-8.
Bertholt to 16-8, heal Kaldach, canto to 16-7.
If Martyn misses:
Liam attack Rider C, 90 chance to hit and kill. Get lance. Can Reliable Attack for autokill if we aren't saving it. Don't bother cantoing. Too many axemen. (7 damage, or 8 damage with reliable attack)
Sam bard Brock and Esther.
Brock to 15-7, hatchet Rider A, 98 chance to kill and get lance. (10 damage)
Kaldach to 17-8, vuln self.
Bertholt to 14-8, heal Roux, canto to 16-7.
Esther to 14-8, swap Roux to using her new sword.
Pros: We sorta get moving. Escape objective, y'know. Martyn does damage on the EP with WTA against most of his attackers (and he doubles axemen), with his PS making him dodgy at near death. No one else can get hit except Roux (who has WTA with her new sword), Sharne (who is on a hill), and Kaldach (meh, this cuts off some attack avenues to Martyn if they go after him). Edit: Farra can also get shot by an archer. But that's probably fine, and she counters.
Cons: Martyn has a somewhat high possibility of getting downed on EP.
Edit: After some consideration, I'll also show my safer plan. It just involves Martyn not moving, which makes the backline cramped. This causes Farra to be the one to swap Roux's weapons and Esther to be slightly more out of place and archer-able.
Sharne to 13-10, stab Rider B (autohit), gets countered and possibly hit. 6 damage, bringing Rider B to 9 HP.
Esther to 12-8, Worm Rider B to death, get sword as reward. 95ish chance to hit. (11 damage)
Farra to 13-9, shoot Rider D. 95 chance to hit. 5 damage, bringing Rider D to 8.
Roux autokill Rider D, get sword, don't canto. (9 damage)
Brock to 14-8, hatchet Rider C. 98 chance to hit. 10 damage, bringing Rider C to 3.
Martyn stays in place, knife Rider C, 81 chance to hit and kill, get lance. (3 damage)
If Martyn hits:
Liam to 15-9, vuln Roux, canto back to 15-8.
If Martyn misses:
Liam attack Rider C, 90 chance to hit and kill. Get lance. Can Reliable Attack for autokill if we aren't saving it. Don't bother cantoing. Too many axemen. (7 damage, or 8 damage with reliable attack)
Then:
Sam bard Brock and Farra.
Brock hatchet Rider A, 98 chance to kill and get lance. (10 damage)
Farra swap Roux to using her new sword.
Kaldach to 17-7.
Bertholt to 16-7, heal Kaldach.
(or Kaldach hold and vuln, Bertholt flail and do nothing)
Pros: No one will go down on EP. Roux can get hit for 10 damage (thank you, WTA and forest tile), putting her at 1 HP if she isn't healed, but that's fine.
Cons: We ain't movin'. Esther can get shot by an archer and is likely to be rather far away from the Guardsman next PP. If Kaldach goes to 17-7, he gets attacked by a mage without being able to counter.
Thoughts? I'd appreciate someone double-checking my calculations as well.