My original words are about a method: 
1. among the 2048 words in BIP-39, cut the first 4 letters out first
2. delete all the words containing these 10 letters, leaving only about 600 candidate words.
3. to uniquely express 12 seed words, each taking the first 4 letters requires 48 letters. Only 46 are given here, so there are 2 words that are 3 letters long, and there are 10 words are 4 letters in length.
4.  run a letter counting program for random combinations of 12 words on the compiled 600-length word list

It's hard to understand from these words that all seed words longer than 4 letters are excluded, right?