I might be too late, but I just tried using a mod allowing more bros, and it fixed your issue in a snap.
(see attached save)
The mod I used was “18 bros in battle (27 total)”, which you could find easily on nexusmods.
It’s not the latest of this kind, but worked well, and let me fire the extra bros&saving before removing the mod and launching the game again to continue as if nothing happened.
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If I can give you an advice for your future runs : never tick “Ironman” again. This isn’t needed as long as you chooses not to cheat anyway !
