In the End of 1 Samuel

So I have been reading through 1 Samuel and I am really excited about some of the things that God is teaching me.
David has gone to live in the border town of Ziklag. Living on the border is never good. David is in compromise- he is telling King Achish that he is doing one thing- but really doing another. Things are going "fine" until the Amalekites (remember them? They are the guys that Saul was suppposed to utterly destroy... but ooops, he didn't) swoop into town and raid the town while the men were away. David and his men return to find their wives and children have been kidnapped, their possessions have been stolen, and their homes have been burned by fire. What now? While the men were angry at David for getting them into this mess and thinking about stoning him, David was "strengthening himself in the Lord." I need that. Anyway, David turns to the Lord and asks what he should do- do we go after them? Will we overtake them?
There were some of his men that were utterly exhausted and unable to go with David and the others on this raid. David has them stay by the Brook Besor (which means refreshment) while they go to recover their families and possessions (though at this point, it isn't clear whether they know the fate of their loved ones... for all the men know, their families are dead).
On his way to try and find the Amalekites, he comes across an Egyptian who was the slave of one and has been left in the wilderness to die. David takes him, feeds him, refreshes him, and asks that he lead David to the camp. When David and his men find the camp, they destoy everyone (except a pesky 400 that escape- it is worded really strangely, which makes me wonder why it is so awkwardly worded. Perhaps it is to show that David TRIED to fully obey unlike Saul that didn't try to fully obey).
When they return after a successful raid- they have killed most of the Amalekites, they have regained their families and their possessions some of the men (the Bible calls them "wicked") try to say that those that stayed behind shouldn't be able to share in the spoil of the Amalekites.
But why does the Bible call them wicked?
I think of two reasons. First, they are trying to pretend that the work that was done was done by themselves. By refusing the blessing of those who didn't go- they are as much as saying that they, themselves had something to do with the victory. But whose victory was it? Man's? or God's? I do that sometimes. Something great happens or something is accomplished and it is truly by the grace and or strength of God that it has happened and I try to take the credit for it. God is teaching me about tithing- that is what I think about. Do I really think the paycheck is for me alone? Do I really think that it isn't a gift from God that I have a paycheck?
The other lesson that I learned has to do with calling. There are people that are called (by God) specifically to do certain works. Romans tells us through the analogy of the body. We can't all be the head. God has given us function, we need to fulfill our function, and not assume our function on others. I need to let God be God in the lives of others and trust that He will call where He wants to call. They will answer in accordance to their calling- God may have to prompt them, and He might encourage me to encourage them in their calling. But ultimately... it is not my deal!