Just an FYI: if your ms is rejected after review by one journal, and you resubmit to a different journal, it’s fairly common for it to go to some or all of the same referees that reviewed it for the first journal. I don’t know exactly how common (how could you ever get data on that?) But it’s not rare. For instance, just in the last few months I’ve twice reviewed an ms I’d previously reviewed for another journal.
Why do journal editors acting independently nevertheless often end up choosing some of the same referees for a given paper? In part because a minority of academics do a majority of the reviewing, so the pool of potential referees isn’t as big as you might think. At least not the in the eyes of editors who like to get reviews from referees whom they know from experience will agree to review and do a good job. In part because many editors use similar criteria for choosing referees. For instance, seeking reviews from leading experts on a topic–who often are few in number, even for topics that you might not think of as narrow or specialized. Many editors also like to seek reviews from people who’ve published on the topic recently, which often isn’t that many people. And in part because, if an ms heavily cites or discusses someone’s work, that someone likely will be asked to review it.*
This means that, as an author, you need to take the reviews of your rejected mss seriously and revise as needed before resubmitting to a different journal (even if only to clarify the ms and prevent misunderstandings you think the first referees had). Do not just resubmit a previously-reviewed ms to a different journal without revising, on the assumption that you got “unlucky” with your referees and that the “new” referees will like your ms. Because the “new” referees could well be the “old” referees–and nothing annoys referees more than authors who ignore their comments!
The flip side of that is that nothing pleases referees more than authors who take their comments seriously and revise appropriately. So do it!
*In case you’re wondering: no, a referee who’s reviewed your ms before for another journal is not “biased” and does not have a “conflict of interest”. Not even if the previous review was negative. See this old post for discussion. Although journals that have double-blind review may avoid referees who’ve learned the authors’ identities by reviewing the ms previously for a journal lacking double-blind review (I’m not sure on this).