Judges 4-5 is about deliverance from an unexpected source.
Culturally, Israel didn't expect women to lead. Deborah is judging Israel but wants Barak to lead the army. He won't unless she goes, too. In other words, he makes her lead, when he should.
Judges 5:2 is the main message. Israel needs leaders, and they need to follow their leaders. But God can deliver even when the "first-string" leaders don't step forward. Esther 4:14 may relate. The rest of Judges is littered with flawed or unexpected leaders that God uses anyway.
The same theme of deliverance from an unexpected place is in the Jael section. Somehow Sisera slips away from the army, but God can see to the downfall (or exaltation) of anyone, regardless of earthly, political or military maneuvers. In this case, He uses Jael. It's a great statement that God's people can "break the mold" sometimes. A woman doesn't always have to have a "gentle and quiet spirit" (1 Peter 3:4) apparently. Unless it's a trick to crush the bad guy!
This relates to Jesus since He is also a deliverer from an unexpected place: Galilee. See the end of John 7. More generally, who'd expect the savior of the world to come from obscure Israel, which was not a major player on the world political stage at any point? Interesting that Zebulun and Naphtali are mentioned in Judges 4:10, and in Isaiah 9:1 when speaking of where Messiah will come from....
The decisive blow of Jael, and Deborah's summoning of the army in Barak's name (4:9), both point to action needed by the leader. Philippians 2:5-11 is very relevant. Hebrews 2:14. Strong language: destroy. I just read a great chapter in "Dragon's Tooth" by N.D. Wilson about this very thing (chpt 15, "An End"). The main character had to kill the bad guy, and it's described graphically - a stab to the temple, actually, now that I think of it...
The glory goes to the one who leads (Judges 4:9-10) - the one who sacrifices. Jesus was in the position to do this, and He does it. Leadership to a T! Earthly leaders are really poor at this - we compromise and we waffle - which is why Judges is so compelling.