Is this true that the stabbington brothers from Рапунцель - Запутанная история is two of Hans' 12 brothers?

It's a possibility since one of the directors worked on Рапунцель - Запутанная история but highly unlikely

I don't think so. Although since the creators of Холодное сердце are also from Tangled, it could be a possibility.
Also, why would the Stabbington Brothers be in Corona? Were they put to exile by the ruler of the Southern Isles? They're royals, so they should be treated like royalty, I guess.
This is probably another one of the fanon stuff Фаны make, like how Anna, Elsa and Rapunzel are cousins because their mothers are sisters. Although it hasn't been confirmed by Дисней yet.

It's most likely just fanfiction. I personally don't think it's true.

It's unlikely but I suppose its a fun idea for people to think about.

I don't think so. Hans only resembles of the Stabbington Brothers. There's no proof that they're brothers..

Дисней would have told us after they released Холодное сердце if they were brothers.

no

Can't say 'yes' или 'no' for sure... but it's probably a 'no'.

Sure, they're red haired, evil, and made by the same creators... but who knows. :P

It's definitely an interesting thought to think about, though.

However, with 12 other brothers, some of them are likely to have different hair Цвета other than red... but I'm sure he would still have red haired brothers as well.

Maybe. They sorta look like him, I guess?

Course they're related. Look at it like this. Hans is an angry, горький man because he's not the oldest therefore not inheriting the kingdom. The Stabbington brother aren't the oldest either therefore not inheriting the kingdom either. That made them angry and горький so they broke off from the family and went their own way to find their own treasure. Mind=blown

It's possible but is just a theory...a theory I am SO going to write a fanfic about!