Dawes and Byrnes were included in the group, announced on Friday, while hard nut Jordie McKenzie was elevated.
Melbourne coach Mark Neeld was pleased with the number of players putting their hands up for leadership positions and singled out McKenzie for praise.
"This group is a sign of the development we've seen in our players over the past year," he said.
"The work that has been done by (director of sports performance) Neil Craig and (backline coach) Jade Rawlings particularly in this area has been outstanding, and has resulted in a large number of players vying for a position in the group.
"Of the three new players to the group, Jordie McKenzie continues his great story, coming from the rookie list to where he is now.
"Jordie's work ethic, competiveness and attention to detail have earned him this position.
"We are also pleased at the impact of Shannon Byrnes and Chris Dawes since their arrival. Their leadership and experience was one of the reasons we pursued them during the free agency and trade periods."
Neeld conceded Grimes and Trengove had a tough introduction to the role but is confident the addition of Jones as vice-captain will ease the pressure on the two youngsters.
"Both Jack Grimes and Jack Trengove experienced a challenging year in 2012, but in their first year as captains, we were very happy with their development and have full confidence that this will continue in 2013," he said.
"Nathan Jones has been recognised for his contributions both on and off the field last season, and he, along with the others' leadership, will provide great support for our captains."There was also praise for the way veteran ruckman Mark Jamar handled his demotion from the leadership group.