@dpendleton ... Looking Great! It's really ones personal preferences as to what width to do those strips. And that might change depending on what fabrics you actually use as to what width will work best.
Though I do tend to agree with you that they may be a bit overpowering at this width. You could try blowing up the online pic and scale it to see what widths they are. I did ... and I think it measured to the 1/2" finish as you suggested. Though 3/4" finished may be a little less fiddly to work with and could still look great.
Regardless you have a great start on your design ... your sample? might make a good throw cushion? Flip side could be your next sample? or have two pillows at different sizes?
Bonus ... if by chance you are using the quilt fabrics for the test run ... you already have coordinating pillows made!
Have Fun! and keep us posted!