that's not true he defeated oro after he joined akastsuki and he was definitely older than that cause when he was 13 he become the anbu captainItachi was about 13 when he defeated Orochimaru. A well known Sannin noted as the strongest. :scorps:
my point is that i scaled down for age as well nagato was 10 at that point while itachi was 13 i think 10 year old nagato would beat 10 itachimastering all the elements doesn't make you the strongest
speed , intelligence, genjutsu, taijutsu, are all still there..
10 year old nagato would never have been able to defeat a sannin.. But 11 yyr itachi did..in seconds