Question about retreat

[DDLAfan]

Joe Johnston lost a battle at Colombus, KY, and instead of retreating to Humboldt he decided to retreat into the swamps of Island No. 10. Since the retreat took longer then 15 days he still remained in Colombus at the end of the turn instead of being in Humboldt if he was smart. At that point he was just bounced around in Colombus until his entire army was destroyed (Union player moved forces into surrounding spaces next turn and Joe kept trying to retreat to the swamp).

Can someone tell me what sort of options are available to a player that could mitigate the randomness of retreats. Do retreating forces go into spaces where friendly forces are located as a priority?

Thanks.

[Jim-NC]

There is a entire retreat algorithm. See this thread (look at post 11)

[Stauffenberg]

Joe also has a propensity to retreat from Nashville / Davidson TN directly east up into the hills of Smith TN, across Stones River, into mud or snow, rather than directly south down the main RR and road towards Alabama or Georgia. The presence of friendly forces does not seem to affect this.
I suppose its time I looked at the retreat algorithm myself.