Hey,
Yes of course you can easily keep several male adult paros in one tank of that size. This is no problem if you provide enough hiding and breeding spots(tubes, 2+ per male)…
Especially if they grow up together, you can keep them without big problems. It is also a good advise to start having at least two tanks per species. If something goes wrong in one of these or if you have problems with single animals, you can seperate them easily. In addition to that, it is sometimes good to isolate younger fry from the parents if you dont have so many of one species and want to make sure as many as possible grow up…
Greetings Rafael