Bingo. Either more words, or fewer grid squares (f.e. instead of 3x3m grid, a 4x4m grid). I truly don't understand why they thought they needed 3m (10ft) of precision: my home has something like 10 What3Words addresses (80 if you count the yard and the other side of the duplex!). The old outhouse at the family ranch has more than one!

IMO, they also should have built redundancy (some form of error checking at least) into the encoding.