A Short Fugato Choral Overture

The first contrapuntal piece I have written after 6 months of composing. Need some advice. 

For only having been composing for 6 months, your grasp of the Baroque style and sense of counterpoint are excellent!

My main question is: why did you write this for voices and not instruments? Since there are no words, and this would be extremely difficult to sing,* why not just use a string quintet instead? Or even woodwinds, who could play these lines pretty easily.

*The fast, wide leaps (e.g. soprano, 2nd line) as well as the fast notes at the extremes of their ranges (soprano m. 12; baritone, m. 17) are almost impossible vocally... and even without them, the harmonic and rhythmic independence of the parts would make this a huge challenge to put together a cappella.

Yes. You're right. Should have wrote this for a string quartet.