Feedback for short composition

I think my answer is not to your question, but I hope it helps.

There's composing and mixing issues. You can "compose" a trumpet solo marked piano, perform in a sample recorded at the forte dynamic level, and reduce the volume in the mix to a lower dB....then you'll get a quiet trumpet that is shouting. Better would be to record the track with a sample layer that was captured in a room at a true piano volume. Most libraries today have multiple dynamic layers and are controlled by CC1, CC11, or velocity. The timbre change is what sells the dynamic. Regarding orchestration, you can mix all kinds of impossible things that would sound terrible in live performance. A difficult mix makes it difficult to judge, and a bad composition isn't worth mixing.

As for your specific excerpt, I think you need to balance your mix to a live reference track. Drop your favorite audio example into your DAW, play in your sample libraries to recreate the original, and try to match your mix to the reference. You can compare the wave forms for relative volume/EQ etc. Also, listening to the live references will give you an idea of the possible and practical usage of the instruments. I look forward to hearing other people chime in.