In big scenario, occasionally we have to retreat from front lines to a better defensible position, several hex away. I was wondering if there are any tips when doing such operation. Get everybody to run and hope for the best doesn't sound like a good strategy, yet we want to minimize the sacrifice. I feel sorry for the Romanians i've send to Gulag during my last retreat playing as Axis

I know several things to note :
- HQ give disengagement bonus (by how much? Does HQ never suffer disengagement attack?)
- High unit recon capability gives higher chance for successful disengagement (Again by how much? Does the recon capability = the chance ?)
Did I miss anything else?
Thanks in advance!