>>9764027
Using a suggestion from another Anon and starting at Q gives this:
000, 001, 002, 010, 011, 012, 020, 021, 022
100, 101, 102, 110, 111, 112, 120, 121, 122
200, 201, 202, 210, 211, 212, 220, 221, 222
_ A B C D E F G H Q R S T U V W X Y
I J K L M N O P Q Z _ A B C D E F G
R S T U V W X Y Z H I J K L M N O P
That would make E 120 so it still doesn't work.
However, if RRR is most frequent and therefore is E
That means it must be 000, 111 or 222
Giving three alphabet orders to try
Or 6 if you are unsure what to do with _ (space).
If we can find one or two more letters, that would crack it.