I did not have much problem with it, until I tried to figure out the third letter in MGSW. For some reason it stumped me for a while. I had to go through the alphabet to get it. I had all the other letters in the puzzle. (I did not look at the clues.) My “breakthrough” was TNOKYAO which letter frequency and pattern gave me. The repeated common letter “O” in that word gave me the word, and the puzzle.
I am not sure I could solve any of these without the letter frequency numbers.
I got it by a longshot guess on the letter pattern in ZWGJJX