Most Sámi are not reindeer herders, and thus are no more nomadic than your average Norwegian. Even going back hundreds of years, many Sámi were primarily fishermen and didn't travel much.
I am not sure what you mean about static fences? Reindeer is semi-wild. They gather them for sure (with helicopters and stuff these days), but outside that the reindeers basically go anywhere they want. Yes, they have ”areas” where they should be, but they are, as mentioned semi-wild animals. I have cottage in Lapland and it is very common to see them on my property almost daily. I like it, but I understand locals do not like it that much, as basically they eat everything you want to grow for yourself (and at north, it is already hard to grow anything).