The game has some built in losses that act like stragglers but it does not keep track of them separately. So that is no "straggler" recovery but there is a built in recovery of casualties in the Campaigns.
Campaign Loss Recover is a straight percentage of all casualties and here are the numbers I have from the last time someone published them. The recover percentage is based on days since previous scenario:
10% for 1-6 days
20% for 7-17 days
30% for 14-30 days
40% for 31-59 days
50% for 60+ days
I am not sure how round off occurs but the few checks I have made indicate the South has an advantage with those little one gun batteries because they always come back.
I don't think the game tracks anything but scenario to scenario. Also I haven't verified how it measures casualties. That is, relative full strength, which is what I suspect, or losses during last battle.
Here is what "I think" happens:
First scenario of campaign a unit loses 90% of its force. 1000 men reduced to 100.
Next scenario which occurs three days later the regiment will be at 190 strength.
That scenario it loses 50% of its force so strength is 95.
Next scenario is two weeks later (20% recovery). The new strength is 276.
But this is really tedious to verify.
