If that's what you understood, I can't help you. At this point it is known that Hikari is the way to go in terms of connection management and performance with Tomcat JDBC being a close second. c3p0 is considered legacy software, it's not really maintained actively anymore and everybody who's doing something serious in the industry has moved away from it.
On the other hand l2j is not considered something serious so c3p0 is good enough, because nobody really knows much about data in here.