I think having a good musical base/knowledge really separates who you are as a musician.

An arranger should be an instrument only to 'enhance' or accompany your performance.

I know a guy who is 'okay' as far as playing the music, but he is REALLY good with utilizing my Triton Studio's arpegiator and other features. I actually prefer to see somebody who is already good with performing only a piano (or a Rhodes) a small drum and a bass. Just my opinion

P.S I tried playing Violin before. My first and only piece was "twinkle twinkle little star"