er.. is compass Lv12 at work for Lv12 NPC?

Trying to learn and understand how the Movement phase works out in a battle. No maths genius enough to work through combat phase but I guess I need to start somewhere.

Of interest here is what is the difference in 3th spearhead and 4th spearhead that determines D archers getting hit and ending the battle in 10 rounds or 11 rounds.