As the poster above me said, if one’s cheating, it’s likely they’re using the out of sync/reload thing.
However, it’s also important to realise that not all high scores are the result of that, as some can just get very lucky with lots of 3k point tasks.
Two weeks ago in Megalopolis, I had a favourable amount of 3k tasks in my first 60 assignments, finishing with 130k. I was even more overjoyed when my first two golden ticket tasks were both 3k too (upgrade 3 Omega homes and launch 3 disasters). As golden ticket tasks repeat in an A-B-A-B pattern, that assured me of an extra 45k points over the 15 golden ticket assignments.
As that was almost the maximum one could hypothetically get, I proceeded to use 15 golden tickets to finish with 175k. About 8 hours from the finishing time, I was top and confident of winning a Megalopolis league for the first time in many many months.
But 2 hours later, I saw that a city had come from nowhere and surpassed me with a mind-boggling 194,000 score. Doing the math, he/she averaged 2,586 points per task. Even more astounding was that the city had come from nowhere (didn’t notice it in the top 10) to suddenly shoot to the top in just a few hours (i know its possible to SimCash one’s way through it).
Supposing he was as lucky as me to get all 3k tasks in his/her 15 golden tickets, it means he outscored me by 19k over the 60 initial assignments.
I was gob-smacked and frustrated, but resigned to the disappointed. I wanted to report the city, but knowing that nothing would be done, ended up not bothering to.