Hi Erin, welcome to the group! As the others have said, all babies are so different. Have you tried putting Charlie in the pram and taking him for a walk in the afternoon? Maybe start a routine of doing it everyday and he might just dose for a 45 minute cycle. Should be enough to keep him fresh for bedtime routine.
Matt lilkes his nap about 3ish but I would love him to do it a bit later, like 4. Because of that he is in bed by 6pm these days. He can't keep his eyes open! But he has been a sleepy babe from the start.

Wanted to say thanks Melissa for the chart. There seems to be an awful lot of cloudy and unsettled days there!