YHPL, ZVPURYYR, and RYRNABE are all both SVEFG YNQVRF and JBZRA VA ORNGYRF FBATF, and could easily be switched around. The items in the two remaining groups could just as easily be split up as, say, ZRA'F ANZRF and ANGB CUBARGVP NYCUNORG

That was the point, but maybe too much crossover.

"Wives of US presidents" not accepted for "US First Ladies" !

The wife of president Bill Clinton is HILLARY, not the double "l" - this shoddy error makes the whole puzzle bad

This wall is fundamentally flawed. There are several full solutions to the wall which are perfectly correct so it is impossible to solve the wall using pure logic. If you get left with two certain groups then all you can do is hope that your guesses match the solution chosen by the author.

Presidents' wives incorrect???

not bad

should only be one or two crossover words, not whole groups.

All the answers in the cars group are also answers for the NATO alphabet group. Too many red herrings for this to be enjoyable!