I am a PhD student now and I have been curious about this question since I was an undergraduate student.
How do researchers choose which journals to submit if your work do not have an obvious fit to a specific one?
After reading some papers, I now have a brief sense, for example, I know Mathematical Programming (A) contains some solid theoretical optimization research, short papers appear in Operations Research Letters or Optimization Letters (what are their differences though?) Operations Research usually contains innovative and new models or algorithms, INFORMS Journal on Computing also contains algorithm research.
Is my sense correct? What about Management Science or POMS or MSOM?