The Germans went right to the heart of the problem (Lappland) and started a scorched earth campaign. For their pains the Finns fought back and sent the Germans packing up through occupied Norway (not South to ships).
There was a major military objective in Northern Finland at the time ~ access to Nikel Oblast. That's where there's a huge nickel/iron meteor imbedded in the Earth that's the source of most of the nickel used in modern industry. Makes Sudbury look like a banana peel for that matter.
There's also a major iron ore range running from Sweden through Finland to Russia. This Northern range was the source of Swedish technological advantages over other Europeans in the Thirty Years War (when the Swedish Empire was established).
The Germans didn't really want to give that spot up.
Recall Nickel Mines in Pennsylvania where the crazy guy killed those Amish girls several years ago? That area was originally settled by Sa'ami Finns from Nikel Oblast ~ they named Nickel Mines after Nikel after the Nickel found there. Commercial mining was done in the 1700s and then the mid-1800s.
Nikel Oblast is also the site of the world's deepest hole.
I accept your explanation. The author wasn’t a general. I do recall now, without digging the book out, that they withdrew through Norway. The book didn’t have a great focus on the strategic level and whether or not they really wanted to go.
The Germans who withdrew weren’t destroyed. I think they left in pretty much good order. In a war that claimed millions and chewed up whole divisions in days the loss of Finland didn’t cost them much in terms of casualties. Loss of a strategic mineral asset wouldn’t have been a good thing but all of your points about nickel were new and interesting to me.
You would probably have to lay the unit diaries down side by side to get an idea of what really happened. My anchor point for judging this is the Das Reich at Normandy.
When comparing the French and German stories about the effectiveness of the resistance in delaying the 2nd SS Panzer Das Reich divisions arrival at the Normandy beach head you’ll find quite a difference in the two sides understanding of the events. The Germans report trivial losses and delays caused by the French while complaining about allied air attacks and mechanical breakdowns. The French believe (or claim) they really whupped the SS. They got Oradour-Sur-Glane for their trouble.
That’s not to say that the Finns weren’t great soldiers. I just think they showed most of their military prowess in fighting against the Russians. I wouldn’t compare what they did to the Russians and against the Germans in anything like equal terms.