Hi, honestly, I did many changes on the arrangement while composing. First I did a draft for organ. Then I change it for 2Oboe, Horn, Bassoon and harpsichord, but I had the problem oboes and bassoon had no time to breath, also Horn was either too high or I had voice crossing with the bass in some parts, which isn't good. Then I try to replace winds for stings. Register and breath problems were solved, but viola part was too weak and the dotted rythm was hardly heard. Finally I replace viola part for english horn.
But I like your idea. I will try to replace again EH for viola and double strings for winds at some parts. I don't like doubling the hole think, but just some parts.
Thanks for your feedback!