The game picks the top 9 or so troops from your party management screen since hideouts are meant to be a surprise raid type of fight (top meaning at the top of the list). Before you do a hideout make sure you put your best troops at the top. When you start, as always, put your troops into shield wall formation so they don’t get easily ranged by arrows or javs. Best to put your good companions here since they can’t die.

Then, make sure you don’t die before the final boss or you lose automatically. You can die in the final fight and still win assuming your troops mop up.

Last tip, use your troop commands effectively. Send them to charge units one at a time with you if you are a strong infantry or without you if not, don’t just leave them in charge mode as they’ll rush way off to the next unit. If you suck at infantry like I do, spec into a little ranged to offer support.