Just for the record, the group project I arranged music for had people who were almost complete beginners in it. I arranged it with three violin parts, two viola parts, and two cello parts. The first violin, first viola, and first cello parts were all playable at lower intermediate level (some 3rd position and moderate use of accidentals); the second violin part was playable at upper beginner level (1st position, simplified rhythms, occasional accidentals); the third violin, second viola, and second cello parts were playable by almost anyone who had played for longer than a month or two (1st position, no accidentals, and no fast notes).

That said, I'm already committed to arranging a Legend of Zelda medley for a similar group project in the near future, and I don't have a ton of free time on my hands for the next month or so.