1)
Why does it say "bEi'lokim Na'aseh Chayil"?
1.
Radak: If our enemies are many, we will make an army bEi'lokim (Metzudas David - with Hashem's help).
2.
Malbim: We will succeed in war only with His help, but not with many troops.
2)
What is the meaning of "Yavus"?
1.
Rashi: He will trample. Radak - this is like "Bosim b'Tit Chutzos" (Zecharyah 10:5). Malbim - our strength did not do so!