Yes, I teach the children that in the majority of cases, the noraml rules apply. Just find where the letters come from. However odd ones do appear.
The usual types, you would ignore the second set as it wastes time [only look at 2nd set if there are 2 answers or its one of these odd types ]
So we could have ball, call last mast: rule last three letters remain the same, how do you find the first letter b to c [ next one up in the alphabet] l to m [the same] So vest would turn into west.
Walsh have a rather interesting one, exact words escape me, but 1 letter was changing each time:
A to E
E to I
the next would be I to O [using the vowels]
To answer your question, yes they can appear, but are not the majority.