Yeah, at first I hated the turn limit and always forgot to follow it, but now it makes a nice challenge.
Fighters are almost necessary. At the least, you should get a fighter up to Captain, which isn't hard if you have a couple meat shields to weaken units for the fighter to finish off. If you don't want to spend time on the fighter, just send Konrad to finish them off. If you play it right, you can easily get Konrad his 2nd level, which grants him leadership, a valuable skill. I mainly try to keep my captain alive instead of using Konrad, so that I can recruit and keep him alive.
I just got to the Crossroads mission, one Paladin, one Knight, one Elvish Rider (I think that's the 2nd level for the Scout), one Marksman, had a Ranger who was about to level in the previous mission, but lost her to an archer skeleton (really have to be more careful where I put my units...), a Druid, a Red Mage, a Captain, a Champion, and a Merman Warrior with the Trident. Everyone else is just a meat shield.