Did Naruto physically need to go into RSM for chakra though or did he do it because Sasuke was whipping out PS etc. Know what I mean? Uchiha don't have much chakra, just potent chakra. Sasuke does have a lot more chakra than usual but what you're saying is quite an assumtion considering Naruto is just a chakra tank while Sasuke's strengths lies in his versatility. Ik that Sasuke doesn't change much throughout his stages while Naruto does. It's too late to look for base Naruto feats but as kids Naruto could make like a thousand clones and seemingly endless rasengans while Sasuke was knackered after a few chidori XD
Like I said earlier in a previous post. That is right. as kids Naruto had more chakra. Even Up until sometime in part2. But as of around the pein arc, things started to change. Naruto gained SM(one of his modes). Sasuke gained MS. Sasuke's chakra level with MS really increased. Same as with EMS. and after rikudou meeting too. Naruto's "overall" chakra increased also as he gained access to SM, then KM/BM and then RSM. But his Base chakra was pretty much unaffected.
Now I understand where you are coming from. Did Naruto go RSM for the chakra or to have access to his avatar/cloak? He went straight to RSM so it's hard to say from that fight alone. But if you take a look at the battles with people like madara, you would see the cloak modes really make a difference. While Naruto is strong, in his base form he can't really bust out his stronger attacks. Attacks which he needed to counter Sasuke with his PS and PS level attacks like Susanoo chidori and susanoo arrow.
Yes, Uchiha chakra is potent. But Sasuke's is large also. Itachi clearly had a low chakra reserve. Madara and Sasuke's are huge. Madara and Sasuke could fight their respective counterparts for like a day and Hashirama and Naruto's overall chakra levels are not jokes.
Doesn't matter how skilled he is at managing his chakra, I would still say Sasuke's chakra greater than base Naruto.