Now these are the chiefs of David's mighty men, who gave him strong support in his kingdom, together with all Israel, to make him king, according to the word of the Lord concerning Israel. This is an account of David's mighty men: Jashobeam, a Hachmonite, was chief of the three. He wielded his spear against 300 whom he killed at one time... (1Ch 11:10-11)
And after six days Jesus took with him Peter and James, and John his brother, and led them up a high mountain by themselves. (Mtt 17:1)
And he allowed no one to follow him except Peter and James and John the brother of James. (Mk 5:37)
There is a striking parallel between David's and Jesus' inner circle. Although they both had many followers there were three specific men of faith that they sought out to be with for specific times and tasks.
I can't help but think there is a kingdom principle here. Just as there is an importance to our large corporate gatherings, our small groups that meet in the home, and our own personal devotions, it would seem that there is also a time to draw to yourself two or three like-minded men of faith to achieve something focused and specific for the advance of God's kingdom.