besides everything stated upon, i also think it would depend on the agent looking at your case and their workload. as well as how fast or slow they work.
everyone's timeline is going to be different. USCIS states that a response should be given within 60 days of receiving the RFE. also, once USCIS approves DACA, they have 90 days to make a decision on the EAD.
now, i am not saying this to be mean or anything but just to be realistic. everyone has different time lines and thus should not compare theirs to anyone else's . RFE or not.