Eh, I think it's a stretch. In the first place, Snow Leopard is not a White Tiger. You just drew superficial similarities based on them both being white cats. As far as I'm aware, Law's polar/arctic theme has little bearing on Byakko. See for example:
The snow leopard/polar theme is just completely superfluous. It has no bearing on this
at all.
All Law has going for him is his nickname being "Tiger".
In contrast, Zoro has:
- "Tiger" as his official animal
- Already used a Tiger based attack against the Punk Hazard Dragon
- Already slew said Dragon back in Punk Hazard:
- Been hinted to slay a Dragon and replicate Ryuma's legend
- Nearly completed the dragon slaying legend in a moment that perfectly mirrors Ryuma's own feat:
- Using the same attack he used to defeat Ryuma:
If there is any Supernova that embodies the legend of Byakko opposing Seiryuu, then it is without a doubt Roronoa Zoro.
I don't understand how one can read all of the above and then claim with a straight face that Law is just as plausible (or even more plausible) a candidate as (than) Zoro. It boggles my mind.
That theory is still far better than anything Law has in his favour; a leopard is not a tiger.