Lose 3? So that's platinum. If a lvl16 is in platinum, then he's most definitely not a noob XD (unless he's just partied up with some1 in plat, but then blame his teammate not the noob). Real noobs get "stuck" in silver (at least until they stop being noobs). Everyone SHOULD be in ranked - they just settle in a rank that represents their current level of play.
A lvl1k silver "veteran" is no better than a lvl16 silver new player. If they're ranked similarly, then most likely the first one has more experience (although if a lvl1k is stuck in silver, then that experience is most likely just a bunch of ingrained bad habits), while the second one has better aim.