You can swap your characters around @Tijn. Right click their names to swap them. It’s a valid tactic if a front liner gets low.
Honestly I should be the last person giving EOTB tips, but here’s what I remembered doing in childhood. Equip the backline characters with daggers, slings & rocks, spells, and anything else ranged. For example I have my wizard holding multiple daggers in his belt and hand (the 3 items on his right) and when I right click it he throws one and equips the next. Then I have to pick them all up again after the battle.
I’d also consider modifying your characters stats to be as high as they can go. I did that and still finding the game challenging. Otherwise I think you’ll just find yourself camping more often. I find it very amusing that I’ll play for a minute, do a battle, then my party needs to rest for 50+ hours to fully heal, then I play again for another minute and repeat haha. These guys will be geriatric by the time they get to the final level.