Dear Robin you wrote:
[...] You should limit lilypond to one staff by saying
\new Staff << \myMusic \myFing >>
That looks better, but it is still not equivalent.
Try changing the s-2 to s_2:
the notehead and the fingering collide.
To avoid that you should also limit lilypond to one voice by saying
\new Staff \new Voice << \myMusic \myFing >>
Thank you Robin! As you probably have seen the third solution it's almost the same you proposed (probably the only difference is I didn't specified "\new Staff" ).