Even if you have one phrase of 12 words in a chaotic order, then the enumeration will take 8916100448256 options. This is unrealistic, you need to remember your scheme, there is no other way.
The number
8916100448256 is 2
24x3 * 312. That has nothing to do with the number of possible combinations you can make with 12 words
:, which is 12! = 479001600. Brute-forcing a seed phrase out of 12 correct but randomized words is not impossible.