Are these XCOM: Enemy Unknown (reboot) victory stats possible without cheating?

Solution 1:

Days before satellite might actually be achievable legitimately. On easy, and I think, normal difficulty, you start with a 2nd satellite. If it's just counting when you get your second sat in the air, then that's all you need. If the lower diff vs higher diff skew is high enough that one seems possible. Especially if it only counts stats from finished games, as Classic and Impossible are more likely to not be submitted.