Static conditions, that will never apply. Difficulty will jump in 3 days and there is no immediate mining with the Prismas. So what you presented is only in your fantasy. It can't apply to the real world. So while they are not false, they are not applicable either. It's just an useless projection.
For crying out loud, you're not the brightest bulb are you? The conditions are not meant to be realistic, they're meant to remove all the variability so you can compare miners without having to guess at values. This provides you with base values which can then be modified based on your estimations of things like difficulty change.
What length of time are you looking for? I just gave you my projection for the first 2 months of mining.
Given a 1 month head start for the Prismas in which they made 1,764 USD (after power costs), how long would it take SP35s to overtake the Prisma in total mining profits? Show you're working as well.
After 60 days of mining, the 2 x SP35s would have made 4.6 * 12 * 60 = 3,312 USD = SPP. Because the Prisma set started mining 1 month earlier, it would have been mining for 3 months and made 4.2 * 14 * 90 = 5,292 USD = AMP.
How many days will it take for the condition SPP > AMP to be true?
Hint: If you use the numbers above, the gap will only widen because 4.6 * 12 < 4.2 * 14.