I usually start out with militia until I have about 14-16 gnomes, at which point I switch to a full squad of defenders, leaving the civilians doing civilian things. I then go for at least 50% split in the civilian/military ratio, until I have sufficient civilians (I found out that about 15 civilians can be enough, however building stuff is going to be very, very slow), then all extras get military professions (which means all training, fighting, sleeping and - unfortunately - dying).
This also works for hard. For quite a long time too, but you will get overwhelmed at some point because military cannot actually keep up with the stack of doom that will happen. I dont use death traps, so the highest I got without anyone dying was about 1.5 million kingdom worth (I have yet to start another kingdom, and have not "finished" the 1.5 million one, because it was a huge time waster with its megaproject. I also wanted to mod the game, and got frustrated a few changes in. Now my life is changing.... Well, we will see
). When the veterans start dying, it sets a downward spiral in motion, as new recruits only come at the start of the season, and they cannot hold a candle to the vast masses of goblins and ogres, and die first - not amounting to much.