Hallo Steve,
If there are no rules then it's not cheating but tricks. If there are rules then you can call it cheating if you wish to! Also nothing is impossible. Every second day up to 400,000 players participate on the event and are probably quite happy when they complete all the games, or an expert in under 5 minutes, or whatever. A 30-game-event will normally take between one-and-a-half to two hours to complete, sometimes a little longer or shorter, these times would be for a player who simply wants to play the game, and will end up somewhere on his leader board (1 to 100). These players will never ever get into the global top 100 but that doesn't worry them!
The next situation that we have is that a player has several other players on his friends board. Now, not to be last on the board he must decrease his playing time. One of the most common methods of doing this is to open a second account, playing the games on the second account, writing down the moves and then playing the game on the first account. Then a 30-game-event will take about an hour.
There are of course other tricks. The completed games are all on YouTube, this is good if there is a problem solving a game! So now we come to a word that everyone has seen "bot" a short word for "robot". A bot just plays the moves it has been given on the game board, it doesn't have to think, it just clicks cards. Using a bot will cut the game time down conciderably! 25 to 35 minutes. Bots can be purchased on the internet, but I would strongly reccomend that you don't download a bot, you could get a lot of problems when you try to use it. Last but not least is a "droid" short for "android". Comes from "Star wars". A droid is a program that not only solves the game, it plays it as well, similar to a computer chess program.
Let's get back to the global top 100, from the times that I have mentioned you can see who is playing with what tricks but that is only 100 out of 400,000 so it's not worth worrying about! Finally the global top ten are playing amongst themselves so these should be of no interest to you.
I hope this helps you.