Should I submit a rejected paper as it is in some other place so that publication decision comes quickly? I am a Phd student (thesis submitted in January 2018, not defended yet) in applied mathematics. My first paper was published in February 2018 in a tier 1 applied math journal, two other papers were recently rejected from tier 1 applied math journals. 

I discussed the rejected papers with my advisor, we decided that we will work on the comments of the reviewers and associate editors and then submit to some other tier 1 journals. Now that will take at leat 5-6 months and then these two paper may get accepted in 2020 in the best case, or in the worst case it could be in 2021 (generally, top tier journals take a long time). 

Now, my advisor is saying that you should publish continually (there should not be gap between publications) and suggested me to submit the rejected paper as it is, but if these two rejected papers are again rejected I will be in trouble. If a paper gets rejected twice then it may be hard to get that paper accepted in future.

What should I do in this situation ? Any help/suggestions will be useful. Thanks in advance.
Ignoring reviewers' comments and simply resubmitting to a different journal sounds like a bad idea to me, for a number of reasons,


While some institutions are obsessed by quantity of publications, quality is at least as important for building a reputation (not to mention more altruistically for actually improving the state of knowledge in the field). If the reviewers have advised you on how to improve it, and if they are not obviously talking rubbish, it seems unwise to discard this advice without a very good reason.
It's entirely possible that the new journal may send it to one or more of the same reviewers as the old one did. There are existing questions on this site from reviewers who this has happened to, and the results are unlikely to be good for you if you have not changed anything. The reviewers are unlikely to recommend acceptance, and the editor may be annoyed if advised of what has happened.
Even if it does get published without revisions in the new journal, the previous reviewers are likely to read it, and it won't do your reputation any good with them.