Rankine's arrival spelt uncertainty for Rowe, whose tenure at West Lakes has now reached its conclusion.
Davis leaves after 11 games for the Crows in six seasons with the club, having plied his trade in multiple roles.
Turner joined the Crows this year through the Mid-Season Draft, however found opportunities at senior level hard to come by due to injury at the start of his time with the club.
After failing to make an appearance at AFL level, the Crows are considering handing Turner a lifeline through the rookie draft.
“It's an unfortunate part of the industry that difficult decisions have to be made each year and we are saying goodbye to three high quality people in James, Ben and Brett,” Crows list manager Justin Reid said.
“They are popular members of our playing group, James and Ben have become much-loved, hard-working and reliable players and while Brett has only been with us a short time, he also earnt the respect of his teammates and coaches by overcoming injury and playing an important role in our SANFL finals campaign.
“Each of them has made a valuable contribution to our Club over their respective journeys, and we wish them well with whatever comes next.”