True some Scandinavian style knives do have notched tangs.This is there for added security to help prevent the tang from being pulled from the handle(the handle is carved to the shape of the tang).This is important if the tang isn't peened at the end of the handle.
They don't mean that the tang's are unsafe to use.All of those knife blanks that you posted are perfectly safe,including KBH-1/0 which i would call more a rabbit stick tang.
None of them are rat tails and none of them are unsafe to use.
They're not as sturdy as a full tang,but the knife isn't used with a baton,it's used for cutting in a cold climate where a full exposed tang would be too cold to grip.
Look at this x ray of some common scandi's
1. Kellam Puukko
2. Kellam Wolverine
3. Mora 510
4. classic mora
Notice that the tangs that don't go all the way through the handle have those same notches,they're there purely as a safety measure.And all of those knives are well thought of in the bushcraft community.
Here's some more
Notice how short the tang is on the Frost Clipper,yet this knife consistently gets good reviews in the field by actual users as a good value bushcrafter.
Now personally i like a full tang,but that doesn't mean there's anything wrong or inherently dangerous with a stick tang.
Here's the stats for those blanks.
High carbon non-laminated blades; non laminated blades do not have soft sides, so they can be made thinner and still retain stiffness. Thinner blades slice better. These all have the classic Mora shape with a slight clip and are hardened to 58 - 59 on the Rockwell scale.
KBH-2/0; 3" (73 mm, 2 15/16" actual measurement, .56" wide, .078" thick), $8
KBH-1/0; 3 1/2" (83 mm, 3 1/4" actual measurement, .68" wide .078" thick), (Discontinued)
KBH-1; 4" (99 mm, 3 7/8" actual measurement, .72" wide, .078" thick),
This blade now has a shorter tang than shown, about 3"$9
KBH-2; 4 1/4" (109 mm, 4 1/4" actual measurement, .78" wide", .098" thick),
This blade now has a shorter tang than shown, about 3". $10 Out of stock
KBH-2A3; 5" (discontinued)
KBH-3; 6" (152 mm, ~6" actual measurement, .87" wide", .098" thick), $14
Measurements are of the blade only, not including the tang. For example the KBH-3 is about 10 1/2" overall.
Above info taken from Ragweed forge (some nice scandi's on there)
www.ragweedforge.com/BladeCatalog.html