I'm not sure what is the right answer but I'll tell you what I done with DS: I kept the feeds and naps and two separate unrelated things until it all just came together(if that makes sense
).
So If he woke up at around the 3 hour mark I would feed him. But if it was less than that and he wasn't showing signs of hunger then I wouldn't. It did mean that sometimes he would be fed just before a nap, and sometimes he would go over 3 hours (if he was sleeping). But it worked for us.
If I remember well it only came all together when we started to move to a 4hr EASY when he was 4.5months.
HTH
xx