Ch. 11: 8 turns
No, I'm not cool enough to get 7 turns like Horace and Sothe. But, I am able to get sexy level ups from Hector and Matthew. Pick your battles, son.
[spoiler=Unit stats]
Hector (3.58/-)
7 Strength
6 Skill
7 Speed
4 Luck
8 Defense
0 Resistance
Matthew (3.1/-)
5 Strength
4 Skill
12 Speed
3 Luck
4 Defense
0 Resistance
Ch. 12: 5 turns
Bartre got the Secret Book, Lowen funneled his Iron Sword to Eliwood, and I spent my time building Eliwood and Rebecca at the bottom while Hector and Matthew handled the top. My reasoning is that in most of my attempts, Marcus never reached in time to do anything significant at the top besides rescue Serra, and since I usually finished early at the bottom for no payoff at the top, I'd figure there's no harm in spending my time a little slower for the two.
[spoiler=Unit stats]
Hector (6.8/-)
10 Strength
9 Skill
8 Speed
4 Luck
8 Defense
1 Resistance
Matthew (4.74/-)
5 Strength
4 Skill
13 Speed
4 Luck
5 Defense
0 Resistance
Serra (1.36/-)
Base
Eliwood (2.03/-)
6 Strength
6 Skill
7 Speed
7 Luck
6 Defense
1 Resistance
Rebecca (1.54/-)
Base
Marcus (-/1.04)
Base
I'll upload the pic of my HNM record sometime tomorrow, it's too late as of now.
Holy shit, your Lowen is awful, Horace.