The first playthrough is rough. What I did was I'd cycle through the first page of the save, saving at the beginning of the day and overwriting the first save when I reached the bottom. For the AOE adventurers, prepare 2-3 traps that grant 1-turn invulnerability and pray your backlines are both covered against AOE. Save scum until they are. Then on your turn, snipe the enemy caster. You can find my general Raid/Defender setup a page back.
P.S. I made to to an ending around day 50 or 60 on my first playthrough. At that point, I decided to just NewGame+ from there because my invincibility traps were running out. Apparently someone's beaten the game in a single playthrough, but it gets significantly easier every loop. By my 2nd NG+, I was already steamrolling everything, even challenging god.