Divides into bands?

Now you have to follow me here.  Genesis 31:17 says, “Then Jacob rose up, and set his sons and his wives upon camels;

31:18 And he carried away all his cattle, and all his goods which he had gotten, the cattle of his getting, which he had gotten in Padanaram, for to go to Isaac his father in the land of Canaan.”  So he fled Laban with his sons and wives and (although it doesn’t say) I am assuming his servants.  Genesis 32:6 says, “And the messengers returned to Jacob, saying, We came to thy brother Esau, and also he cometh to meet thee, and four hundred men with him.”  Now Jacob's little group is beset upon by over 400 men.  Genesis 32:7 says, “Then Jacob was greatly afraid and distressed: and he divided the people that was with him, and the flocks, and herds, and the camels, into two bands;

32:8 And said, If Esau come to the one company, and smite it, then the other company which is left shall escape.”  Now let me get this straight.  Jacob divided his group of what, 20 people into two bands?  10 people make up a band?  If one band is smitten and they don’t find Jacob with them wont they continue till they find Jacob?  All would die in this situation. 

But it gets better.  Genesis 32:22 says, “And he rose up that night, and took his two wives, and his two womenservants, and his eleven sons, and passed over the ford Jabbok.”  I thought he divided into two bands.  Who is in the other band?