Not napping

My twins will be 2 in January and one of them sleep great! All night and loves to take his naps. My other twin is completely opposite when it comes to his nap. I will put them both down for a nap and one will sleep for 2 hours or more and the other one only naps for 30-45 minutes. Is it ok for him to only take a short nap or should he be sleeping for 2 hours?

He seems fine during the day with only a 30 minute nap but even when i put him down for bed at 7:30 it takes him forever to fall asleep, you would think he would pass out quick from not having much of a nap.

Is there a way to fix this or just let him take his quick cat nap?