The Roman numerals are traditionally used to indicate strings, not positions. I is the top string (A on cello), and they go in order across the instrument so that IV is the lowest string (C on cello).
Also, it appears there are two different fingering options given. My knowledge of cello fingering is minimal, but I think the Roman numerals go with the fingerings printed below the notes.
@Mouse, I'm not fluent in anything but treble clef... but I looked at
and it appears that each triad starts on "C" an octave apart. I really need to continue those piano lessons I started back in the 50's !!!
If I saw that notation in any music I play, I'd probably have to change my britches
Bob in Lone Oak, Texas