It's necessary to leave off the first  .+ entirely and sort all the captured alternations by length decreasing (or some similar approach). Just making the first  .+ non-greedy is not sufficient to find the longest match anywhere in the string:

>perl -wMstrict -lE
"say q{'}, /^.+?(s m e f|s f pl|s f).+$/, q{' at offset }, $-[1]
   for '-s f s f pl s m e f-';
"
's f' at offset 1
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