The first prototype is rarely good. That is why it exists.
It tells the truth faster than a sketch can. The pocket is wrong. The strap is too narrow. The seam order makes no sense. Good.
A prototype that reveals problems has done its job.
First prototype
The first prototype is often flawed but serves its purpose by quickly uncovering design issues such as incorrect pocket placement, narrow straps, and illogical seam order. Its ability to reveal problems indicates that it has fulfilled its role effectively.
Lessons