You can't go past the lines, but anywhere behind them is a-okay. There's tactical reasons to start farther behind the line than usual.
Webm related. Mainoumi was a smaller guy who beat much larger dudes by being athletic, a good technician, and doing crazy shit like leaping around people at the tachiai. Here Takatoriki starts far back to stop any shenanigans.
Nobody but Hakuho knows why he started that far back, but it clearly fucked with Shodai's head. Hakuho's a master at mind games so it's very in character for him.