I don't know why people always doubt Slovenia. Every time they get overlooked and every time they remind people that they're right up there with Lithuania, Croatia, Serbia, etc.
A major switch in generations.
For european standards out of Rasho, Brezec, E.Lorbek, Smodiš, Nachbar, Jagodnik, Gorenc, Tušek, Milič, Lakovič, Bečirovič, Udrih, Vujačič, G.Dragič, Slokar and some other specialist players... those were some sick potential teams, arguably most stacked potential NT in europe at some times, yet always without exemption underperforming at one point of the eliminating stages from one reason to another. One factor accordingly is the fact that since Slovenia didn't manage to win anything with those players it's really hard to believe with could do it with... one third that talent or so.
With the switch in generations, we're producing a surprising ammount of guards unlike most other countries with smaller player bases that ussualy live and die off their centers.
Evenmore with the international 3pointer being moved by half a meter (1.6 feet towards the NBA one), not really sure that was a matter of planned development, most of these players just love to penetrate and are decently athletic along. A lot of other NT's haven't yet made that transition to the way basketball is optimaly played atm.
So basicaly the strenght of this Slo team isn't in individual quality (if that was the case, we're... 7th, 8th, 9th in europe, maybee worse) but in the fact our perimeter is a mold of good defenders, penetrators and recently all of them are improving their shooting skills while a lot of them (Dragic bros., Blažič, Murič, Klobučar) were actually really terrible shooters in youth cathegories. Vast majority of teams lack the talent pool to be able to pick 12 players for a specific game plan, we somehow got lucky and got 7-8 players that actually work great when together on court. Individualy sure both Dragič's are great, others aren't exactly bad either, but they're not in the talent range some other NT's posses.
