1. Otniel is from shevet Yehuda. He is a transitional “shofet.” Fought with Aram Naharaim. This war is idiosyncratic – the tables are turned Aram comes down to fight them! First he judged Israel and then he went out to war. On one hand the sefer gives some details, on the other it combines the judging with the war.
2. Ehud is from shevet Binyamin. The national nemesis was Eglon. Ehud took initiative! He was chosen to bring an offering and changed it to a rebellion himself.
3. Shamgar-Not much can be said about Shamgar, other than his length of rule.

In the fourth Perek, we meet Devorah who tells Barak to wage war. Barak won’t go without her. Barak wages against Sisra who gets confused and runs to Hever HaKeini (with whom he has a treaty) to save him. Ya’el invites him in and kills him. Thus the war is won!

 It is fascinating to note that Rav Avigdor Nebentzahl Shlita notes that the cycles continues to play a key role here. When the Jews continue to sin during the conquests of Otniel and Ehud where battles were fought with large armies, Barak was only permitted to take 10,000 men. It isn't in the stregth of the armies that Jews conquer but rather in the strength of their belief in Hashem.