Are there really hundreds of different jobs or careers that you want? I have only ever tailored my cv and cover letter for the exact position that I was applying for so that they knew I knew everything about the company and what they were doing and why they needed me to help them solve their problems. When they read my Cv they are like thank god our search is over, this guy can do it. Because it you are going to get the job you can do it and you will do it! It might take some training and some extra hours to get up to speed if your experience isn’t an exact match but you can say that, I’m going the extra mile to make this relationship a success, to make this deal work so that we both get what we want. People want to work with people that are happy to be there. If there are hundreds of different jobs you could have to me that says you don’t really care about any of them. Find the one job you desperately want and go after that.