Warriors (particularly medieval warriors, which is the type of setting Fire Emblem is based on) would never really fear death that much.
I mean the heroes that all of these warriors looked up to were heroes because that killed a shit load of people and were amazing warriors who were not afraid to get down and dirty. The role of a general, commander, tactician and others is to make tactics that will win with the least amount of casualties possible. Yes Ephraim is headstrong and reckless in the beginning but he evolves into an amazing king and leader, not to mention the other role of a general/king/commander: to inspire his troops, which, as I mentioned about Forde, Kyle and Seth, Ephraim is amazing at. His soldiers not only willingly risk their lives for him as they do it GLADLY.
That's the mark of a good leader, as well as the fact that he never picks fights he can't win (was that joke made already?)
He's reckless at times, but he's still careful, calculated, an amazing tactician and an amazing fighter.
As good of a tactician as Roy seems to be... I'd be a lot happier serving someone that actually can get shit done themselves.