No last movie Naruto is stronger he still has rikuodo powers.If you're talking about the Naruto that fought Toneri and you're comparing him to Six Path Naruto then he's way way weaker than Six Paths Naruto.
He wouldn't need to seek them out. Naruto's body is the meeting place for all the tailed beasts. Kurama simply has to "summon" them and then they can all share chakra and what-not.No, no Yang Seal.
If he sought out the Bijuu and requested some more chakra, then he could access RSM and with all the extra experience and the fact that his body has fully matured, he would be on par, if not stronger than himself in the War Arc.
Unless you mean BSM Naruto from the War, in which case, KCSM Naruto > BSM Naruto because he has the complete Kyuubi and extra experience and more honed skills.