Mercenaries
Highborn Covenant
PCs: 50 / 50
36 models
[00] Ashlynn D'elyse (0 / 6 WJ remaining)
[02] >> Sylys Wyshnalyrr, the Seeker
[09] >> Rocinante
[09] >> Gallant
[02] Rhupert Carvolo, Piper of Ord
[03] Eiryss, Angel of Retribution
[02] Bosun Grogspar
[02] Doc Killingsworth
[02] Lord Rockbottom, Expedition Financier
[02] Harlan Versh, Illuminated One
[04] Lady Aiyana & Master Holt
[08] Sea Dog Crew (9 grunts)
[02] >> Mr. Walls, the Quartermaster
[03] >> Sea Dog Crew Rifleman (3 Riflemen)
[06] Press Gangers (9 grunts)
So theory behind this list is I can deal with ARM because I have Gallant and Rocinante, two P+S 17 heavies and two ARM fixers in Eiryss and Aiyana and Holt. I also have both guard dog and a shield guard for Ashlynn to help her get forward safely and Wyshnalyr to increase the range of her spells and give her some extra focus. Versh helps focus efficiency too giving an additional focus to the Gallant which is why I'm not too worried about her running two heavies. When I charge in, particularly on feat turn Rocinante only needs one to boost damage on his gun and Gallant only needs two because of his accumulator. 3 focus is the same as running only one heavy.
Now the bit I really like, the pirates. Both pirate units get advance deployment as do all the solos. If you go first you quicken the press gangers and then run. You deploy 10" your opponent deploys 7" (17") you advance deploy 6" (23") and run 16" (39"). So you are 9" from their deployment line and 3" from their AD line. With a 4+ tough unit with no knock down, DEF 15 from shooting. It's going to be very hard for much of your opponent to get past this unit. Next turn the Sea Dogs hit boosted by the feat and protected by the feat, still 4+ tough, though you've probably lost no knock down (since Grogspar is on a medium base). At the end of this round you can score, Ashlynn gets into the scoring zone to dominate, if you dominate on your opponents turn the game is pretty much over. Your opponent is still stuck in their advance deployment zone. They can trample over stuff with jacks/beasts but then they cop the sea dogs + the ARM fixers or the Gallant and they are going to leave their caster and whatever else doesn't trample facing units that can boost their attack rolls.
So while this list is especially brutal when you go first I still like it when you go second. Your Sea Dogs are going to shoot your opponent turn 1, their threat range shooting is 1" out of your opponents advance deployment line. They can also charge 13" (with 0.5" reach) so if your opponent advance deployed and ran or moved more than 12" you can safely declare a charge turn1. It still gets way up into the middle of the table. Ashlynn can get forward with the protection from her jacks (and admonition if you are feeling threatened). She can often dominate the closer objective without difficulty, throw out distractions and feed both her jacks. Pirates are DEF 13, 15 against range with Quicken and their super tough works combined with the feat makes it so hard to slog through them.
UPDATE:
There has been a very small amount of playtesting and some points crunching and unfortunately the list I went out and designed specifically to not have forge guard now has forge guard. Le sigh. They are just the best option she has available for killing heavies other than bringing in a Galleon. The current list:
Mercenaries
Highborn Covenant
PCs: 50 / 50
53 models
[00] Ashlynn D'elyse (0 / 6 WJ remaining)
[02] >> Sylys Wyshnalyrr, the Seeker
[09] >> Rocinante
[02] Rhupert Carvolo, Piper of Ord
[02] Gorman Di Wulfe, Rogue Alchemist
[03] Eiryss, Angel of Retribution
[02] Bosun Grogspar
[02] Doc Killingsworth
[02] Lord Rockbottom, Expedition Financier
[05] Alexia Ciannor & the Risen (9)
[08] Horgenhold Forge Guard (9 grunts)
[08] Sea Dog Crew (9 grunts)
[02] >> Mr. Walls, the Quartermaster
[03] >> Sea Dog Crew Rifleman (3 Riflemen)
[06] Press Gangers (9 grunts)
Still doesn't infringe on the characters in my Bart Galleon list which is important. The only thing that may change is that Alexia or three riflemen and Gorman may be switched out for a Vanguard. The list still plays the same. Quickened press gang jam my opponent and try to set the battle line so that all the scoring zones are behind my pirates. Sea Dogs in behing the press gang and Forge Guard mop up anything that has managed to get past the pirates.