chance to freeze is just an affix, like loh for example.
the chance to proc from tornado hits is 8%.
from those 8% hits only 20% or whatever your chance to freeze is get to work.
so the actual chance to proc from rltw tornadoes is 1.6% which is extremely low.
even with 100% chance to freeze only 8% of tornado hits would proc it.
ww has slightly more proc chance but still pretty low compared to other skills.
There's a slight difference here. LOH happens every hit, amount multiplied with with proc coef. Freeze is similar to crit chance, the 'chance' is calculated every hit.
The wind attacks per second increases and have dot which actually stacks.
WW with slightly more proc chance .26, say in with atk spd of 2, your WW hit twice per second.
Likewise, RLTW, each wind hit twice, but each cast will have 4 nados which last for 3 sec.
So in 3 Sec, you have 2 X 4 X 3 X .24 for each cast of RLTW, while the same 3 seconds WW only gives 2 X 3 X .26
You can opt to have both though, the idea of cc proc is to stack as many chances as possible within a shortest time frame. This is the same reason why CM/ET wizards stacks so much apoc/crit chance/atk spd.
Their purpose is slightly straight forward since they need to get off 9 crits within 3 sec(freeze duration) to refresh cooldown on coldsnap.
Freezing barb need to have the chance to freeze as high as possible, since the maximum roll for freeze in all possible gears is 40%, losing dps from both weapons (20 from azurewrath and 5 in MH).
If the concern is not about permanent freezing, throwing in other CC like stuns in gloves will keep mob CC almost infinity.
So in weapon master, mighty weapons gives 3 fury per hit, while 10% chance for axe/mace per hit.