Bro what the fuck are these guys smoking
the "not being a teenager" juice mostly. ACE stonks go brrr.
EDIT: After a quick calculation, Hazo is recently 17 and has had ~5 years of training since graduation. Very good years with various IC/OOC bonuses improving his mildly above average base rate, but still 5 years. He had ACE for like 2 of those years. Assuming Asuma had it as a genin, he's had like 20 years to get XP and buy ACE. 20 purchases of ACE costs 2,300 XP, which is a lot but it also doubles your chakra without needing to buy more CR or fiddle with pyramid slots. CR 50 costs 2,550 XP doublecosted and 60 would be 3,660 XP. CR 50 with 20 ACE purchases is a thousand chakra, a bit more than triple Hazo's reserves of 315.
Similarly, the question of how the fuck Orochimaru has like 2,000 chakra came up. Orochimaru is in his 50s, call that 40 ACE purchases because why the fuck not. 8,600 XP on 40 ACE purchases tripling his chakra reserves, 4,556 XP on 67 CR. It's a ridiculous amount of XP to spend but it does explain how he could have ~2k chakra.
EDIT 2 ELECTRIC BOOGALOO: Nevermind, you can only buy copies of ACE up to your CR AB. So either some other shenanigans are afoot or Asuma and Orochimaru both got a better version of ACE early enough to spam it harder. A more realistic Asuma has CR 50s and 6 ACEs or CR 60s and 7 ACEs, for... 650ish chakra in the former case or 800ish chakra in the latter case.