There’s a difference between a wildcard search in the search bar, and wildcards in client relevance to build an automatic group. The relevance might be a good case for Regular Expressions (which is a handy skill to have in any case, useful in lots of programming languages).
For your first set of hosts, you could use relevance
computer name as uppercase = regex “(^S.*X$)”
That is, the computer name
starts with S ( ^S )
has an unlimited number of other characters ( .* )
ends with X ( X$ )
If you want to match multiple different strings, you can separate them with pipe symbols. I can’t test this now, but I think your second post should match something like
computer name as uppercase= regex “(^S.*X$)|(^S.*PX$)|(^S.*PX-H$)|(^S.*DX$)”
which might simplify to
computer name as lowercase = regex"(^S.*(X|PX|PX\-H|DX))$"
for “Starts with S, has some other characters, and ends with either X or PX or PX-H or DX”