The plan was to put the bulk of the three armies on the two spurs of the mountain that walled the entrance valley. They would then man the valley with only a small contingent, hoping to lure the Orc and Wargs into the valley where they would be outflanked from higher ground.
Bilbo Baggins was famously a hobbit, not a dwarf.
No they are not. Bilbo is simple hobbit from the Shire, Thorin is a dwarf.
Thorin Oakenshield
{| |- | Thorin was the elder dwarf in The Hobbit. He was the one in charge of the expedition to the Lonely Mountain. He had some small magic, but was a pretty good leader. He died in the Battle of the Five Armies. |}
Dain is Thorin's cousin, a Dwarf from the Iron Hills. Thorin sends a raven to summon Dain and his army to help defend the treasure under the Lonely Mountain from the men and elves after Smaug is slain. Dain and Thorin join forces with the men and elves to defeat the evil creatures. He is crowned King under the Mountain after Thorin dies in the Battle of Five Armies.
The first dwarf to arrive was Dwalin. The last to arrive with Gandalf were Bifur, Bofur, Bombur, and Thorin.
Thorin Oakenshield became the leader of the expedition in "The Hobbit." He was a dwarf prince seeking to reclaim his kingdom and treasure from the dragon Smaug.
With Gandalf and the dwarf Thorin Oakenshield, and his company of twelve further dwarves.
That would be 'Ori'
In Tolkien's "The Hobbit," after he had found the cells of the other twelve dwarfs, Bilbo overheard the guards talking about another dwarf, who he guessed must be Thorin. By using the ring, he was able to follow the guards, undetected and find the cells of each dwarf.
Thorin Oakenshield was the head of the group of dwarves.
If you are referring to near the end of the book where Thorin rejects Bilbo, it is because of a dwarf's greediness for gold and treasure. Thorin had been searching for the Arkenstone of his father, Thrain, in the Lonely Mountain, and was upset that he could not find it. He was shocked when he found out that the very Hobbit that the dwarves had put all of their trust in had betrayed them and found the Arkenstone and did not tell him. Bottom line, dwarves are greedy. Hope this answer helped. :)