Oh no, no way. Child violence on the streets and in school is WAY higher, it's ingrained in culture. It's also pretty rare if a Russian kid would tell his parents about it (only if property damage is involved).
I don't know how your link gathers data (website only shows one dude, software engineer, not a professional survey statistician), but from personal experience I can surely say it's rankings are BS.
The closest in US are the "bad towns" like East Palo Alto or some neighborhoods of Oakland, with their respect for ex-cons and prison slang.
1) Russia is generally very safe, and 2) I agree that the violence amongst children is crazy. It’s a great place to homeschool and free-range and I have not found a way to send children to school in a way that’s acceptable to us.