I did some calcs for my plan.
Please note that morale checks are highly variable depending on the previous results, and I'm assuming morale checks roll their mean value.
45th/72nd Attacks Calcs,
Morale Check
5 melee attacks against the 155th 96.72% chance chance to do 50 or more casualties, 69.64% chance to do 100 or more, 22.64% chance to do 150 or more. 1 melee attack against the 74th has a 7% chance to do 50 or more casualties.
As for morale checks the 155th is on 19 stress, that plus a morale check/morale check from being in melee should rout them. As for the the 74th, they have 13 Stress, face a disadvantaged morale check from a friendly unit being routed, and then a morale check from being in melee.
The morale check from just a disadvantaged morale check has a 84% chance to rout. And the second morale check has a guaranteed chance to rout.
Calcs against 20th/33rd Dwa,
Morale Checks
Against the 33rd Dwa, 81.90% chance to do 100 casualties or more, 36.22% do 150 or more.
For 33rd, there's a likely chance for one morale check, and one disadvantaged morale check.
Against the 20th, 84.38% to do 50 casualties or more, 42.35% to do 100 or more. For the 20th, there's a likely chance for one morale check from halfling ambush, and 1 from casualties.
Assuming 2 units have routed, for +1 Momentum.
33rd - has taken 20 Stress, for a final -18 Morale Modifier
1 Morale Check (98.88%) - 90% chance of routing
1 Disadvantaged Morale Check (81.90%) - Guaranteed Rout
20th - has taken 0 Stress, for a final +2 Morale Modifier
1 Morale Check (100%) - Mean 4 Stress Loss
1 Morale Check (84.38%) - 10% Chance of Rout
1 Disadvantaged Morale Check (42.35%) - 57.75% Chance of Rout
Guillory Cavalry - Assuming 2 units have routed, for +1 Momentum.
Calcs,
Morale Checks
I assume that the has 341st Cav charge/Ambush and the 350th has Cav Charge/Rear/Ambush
74.90% to do 50 casualties or more.
Morale Checks
341st
Disadvantage Morale Check (Cav Charge)* - Mean Stress Loss 4 - 25% Chance to Rout
Morale Check (ambush) - 20% Chance to Rout
350th
Disadvantage Morale Check (Cav Charge)* - 65% Chance to rout
Morale Check (ambush) - Assume best Morale check last time, 80% Chance to Rout
Morale Check (Rear Attack), Assume best Morale check last time, Always Rout
Both Attack Go Through
Morale Check (50 Casualties)(74.90%), Already Routed
Morale Check (In Melee), Already Routed
Nymph Ambush,
Morale Checks
Getting morale checks from casualties is unlikely, with a 21.56% chance to get at least 50 casualties. However, we will likely get 3 morale checks, 2 from ambush and 1 from ending turn taking a melee attack. Assuming +2 Momentum from 3 trained units being routed, we have a 15% chance for the second morale check to be a rout, and 45% for the third to be a rout.
Assuming 4 trained units rout, for a +3 Momentum, that's a 20% chance to rout on the second morale check, that's a 50% chance to rout on the final check. Assuming 5 trained units rout, that's a 30% chance to rout on the second check, and a 65% chance to rout on the final check.
13th Hob Lancers,
Calcs,
Morale Check (Assuming 4 units have routed)
Rear cav charge with lances, 86.15% to do 50 or more casualties.
Disadvantage Morale Check* (Cav Charge) - 35% to rout
Morale Check (Rear Attack) - 45% Chance to rout
Morale Check (50 Casualties)(86.15%) - Assuming highest roll last time - 90% Chance to rout
Morale Check (In Melee) - Assuming highest roll last time - Always Rout
Morale Check (Lances?) - Always Rout
Overall Conclusions:
42nd/45th: Should basically always rout the 155th/74th.
Once the 155th/74th have routed Guillory Cavalry basically always rout the 9th if both charges go off. The 33rd Dwarf has a high chance of routing even if only 2 units have routed, 20th has a lower rout rate. For the nymphs, once a few units are routed they have a devent chance to rout.
As for any changes to my plan. The unit order should be 42nd/45th, then Guillory, and the routing the 33rd Dwarf, and then the 20th. As for changing orders, maybe at least oneunit could be moved off the 33rd Dwarf be exchanged to target another unit.
Verus the 33rd Dwarf. The 10th/84th has a 94.54% to do 50 casualties or more, 56.11% to do 100 or more. The 10th/72nd has a 95.39% to do 50 or more, 50.99% to do 100 or more. The 84th/72nd Human has a 68.31% chance to do 50 or more, and 15.89% to do 100 or more.
So we probably don't want to move the 10th. The 10th/72nd is probably the best. Now redoing the stress for the 20th Dwarf given 4 units have routed, or +3 momentum,
Morale Checks
20th - has taken 0 Stress, for a final +0 Morale Modifier
1 Morale Check (100% (Halfing Ambush) - Mean 4 Stress Loss
1 Morale Check (84.38%) - 20% Chance of Rout, Mean Stress Rout of 6
1 Disadvantaged Morale Check (42.35%) - 75% Chance of Rout
75% if pretty good, however we only have a 42.35% to get that check. So we can move the 84th to attack the 20th.
Calcs, 94.86% to do 50+ casualties, 71.40% to do 100+ casualties, and 32.75% to do 150+ casualties.
Summary: The unit will be 42nd/45th acts first, then Guillory, and the routing the 33rd Dwarf, and then the 20th (I'll change the 84th to fire on the 20th). We have a very likely chance to rout the 74th/155th/9th, pretty high chances to route the 20th and 33rd and whatever the 13th lancers charge, and a good chance to rout the nymphs. Overall we could rout 7 units if things go prefectly. Now we shouldn't get our hopes high given how morale checks are pretty dependant on previous results, a possible ready action from the 9th, or Trotha withdrawing from the West (which if things go well in the center/right is pretty likely), but even with poor luck we should rout at least a few units.
*And as a note on calcs, to calc morale checks with disadvantage I either did subtracted by (333/100) or did output [lowest of 1d20-12 and 1d20-12]. The former method does give very slightly off numbers for the mean so it's fine for calculating stress loss from the mean, but output [lowest of 1d20-12 and 1d20-12] gives better odds at getting a lower number than output [lowest of 1d20-12-(333/100)]. [lowest of 1d20-12 and 1d20-12] has a 57.57% to get -5, while -(333/100) has a 50% to get -5.