I don't think top players use alt to attack them self. We are more then 9000 players in this event. To find yourself amongst 1000 other players would take 5-10 min.
Top players get 30-60 defensive wins per hour an average so unless they have hired 10 people to attack them 24/7 they would not get so many kills per hour.

What is going on is this - Most weak players play Moe (guides advised them to do so). So the top players all play Sexy trap deck and the weak players fall for the traps all the time. A poor Moe deck almost always loose to a perfect Sexy trap deck.
Some players migth also want to see what deck the top players are using to copy them - So they find and attack the top players...

If a player have a good offensive deck and know how to use it the player would have almost 100% win chance. I got 120 wins in a row vs. random rank 1 Moe decks when attacking.

M>S>B>M>S>B