Not sure how can you copy all competitors backlinks from ahref and then have them in Scrapebox (don’t use it and don’t have experience in this thing) and then expect the Scrapebox to just comment for you. The backlinks could be posts, profile links, niche edits and many other things. It may not be a site that have posts, in which your competitor posted or commented and you can do the same.
mid this your money site: I suggest that you treat it as a baby and take every backlink you add to it seriously.
may be you can see what your competitors backlinks are and study their strategies (if any) and write up a plan to beat them up and start working on your own better strategy, copy some of their good backlinks, don’t copy the spammy ones and so on.