Lowe's has a proprietary name with Bruce products but that sounds similar to Dundee or Bristol strip. What you describe is par for the course with Bruce such as bowed boards, different widths, and shorts.
Having said that I am used to it and can make it work fine. You should have stopped this job and made a phone call instead of continuing. If you would take a speed square or framing square and check the butt joints you may find that that most are cut square.
There is a different technique an installer has to use to install badly bowed boards so the butt joints will meet up tight and square.
Check that squareness issue out for us with boards already installed and appear to have a mis cut for squareness. Don't take this post as being critical.... just trying to see what is going on here.