From: Hex X37, Y15
...so I take it the conclusion of the group is that evacuating more than 1 is nice if you have the luxury, but not something to agonize over? In other words, if you are stretched and every +1 you evacuate over the minimum limits your ability to evac armament points, you do the minimum
I'm not sure it I'd put it like that... Personally, for anything worth evacuating, I try to evacuate at least 50%, if you only evac 1 unit, it might not reach full production for a long long time. Unless I'd already lost lots of arm points, I'd sacrifice a few of those to get out more tank factory units.
While getting out 1 unit is far better than getting out nothing, I would try very hard to get out more than that (here I'm especially talking about the tank factories).
+1. And many factories are much cheaper in terms of rail capacity than ARM.