Here's a small walkthrough I did for the game frontier (in order to win fast, with the Buccaners):

1. Make your character have max strenght and 2 defence.
2. You'll start with 5,000 gold, buy a claymore.
3. Join the Buccaners (if you join the enforcers you cannot loot sick people, so it's a bit slower).
4. Start killing around and looting. You'll eventually go up rank. (you won't defeat carted people though)
5. Stop JUST BEFORE the delivery quest. You should have enough gold to buy the best armor. If not, kill a few people, loot them and buy it.
6. Complete the quest.
7. Now, restart killing around, but this time you can even defeat covered wagons.
8. Buy the items needed to get the cart, then get it.
9. Pick up a sick person while traveling. If he is weak, fire him. If you're lucky you can even get a person with full attack and defence. Give him the best weapon and armor.
10. Continue looting, flee if needed, but you should even be able to kill Vanguards.
11. Go up rank until the second delivery quest.
12. Get 10,000 gold, then go to one of the towns in the far right and buy 10 cloth and 1 diamond (about 10,000 gold since diamonds are cheaper there).
13. Get a vanguard.
14. Get a bunch of warriors, equip them with the best weapons, then kill the final boss (the enforcer robot).

Hope that helped!