McGrath, Parish, Francis and McNeice are all in their first two seasons and have played this year. Langford has been played and now gone back to the VFL to specifically work on aspects of his game where he can get big midfield minutes. Regardless of what you think of this the coaches have been very open about this and he was always going to have to build up sustained form to get back into the seniors. He and Laverde will be back eventually though.
This is in addition to adding Green and Stewart this year on top of Hartley, Brown, Tippa, Kelly and Dea last year. Oh, and there's the least experienced footballer on the list in McKenna who has been backed in by Woosh and co.
That's a huge turnover of players in a short time, and I can't remember as big a change to the team in the last 20 years, without even taking into account the suspended players returning. I don't think Howlett getting the odd game undoes any of that work, especially without any of the 1st and 2nd year players demanding a game in the VFL.