i didn't get more than 6 at the same time i guess but idk i don't focus on wht it says i just spam opening. but i guess normal is 3-6
if i would have got 12 at one crate i guess i would have noticed it, maybe you opened premium shipments instead of normal ones ? those have 2x token which could lead to 12.
for the spinning wheel well it's hardly about luck you could get the same 3perk card in a short time or you can spend almost 1000token to get what you want ( i recently spend 700 token for 1 card).
to see if there is something different you need a large number to disprove that its not based on luck.
thats the thing in gambling you could win first try and you could lose 5times even with a 90% chance.