TOURNAMENTS: Can someone explain the ratings?

can someone please explain to me why these under 800 players are dominating the tournament?

it's just annoying sometimes

It is an arena tournament: while a higher rated player there thinks on their 3rd move a lower rated player wins their 3rd game

Rating based arenas are designed in a way that anyone can top the standings. In most games, players are playing other members close to their rating.

i'm just wondering, is it possible that the 800 players have a low rated account just for tournaments but their actual account is like 2000+? (Like they have 2 accounts, 1 to grind tournaments using the lower rated account and the other account to actually train, like the 2000+ account)