Separation anxiety or wanting to play more or drop a nap?

My almost 13 month old b/g twins are battling the second nap of the day and I don't know if it's bc thye need to drop a nap or what?
Currently they sleep thru the night (7 pm till 7 ish am) take an hour and a half to two hr nap from 10-12 then I try to put them down again at 3 or 315 and I hear crying or chatters or they're jumping for almost the entire nap. My girl mostly cries while my boy just chatters and sits in his crib.
It hasn't seem to effect their going to sleep and they fall asleep at night easily without crying.
I just don't think they should drop their afternoon nap but then because they wake up close to noon from their morning nap I can't really put them down at 4 pm bc I have to wake them at 430 to protect their bedtime.
Both have separation anxiety so I think it could be that but then again they go down much more easily in the morning.
What to you guys think?

 

Go to 1 nap by starting their first nap around 12-12:30, and plan on putting them to bed earlier at night if they seem tired.

 

That's the age mine went to one nap. Gradually push back the first nap. And you may need an earlier bedtime during the transition period.

 

Thanks for your suggestions! I'm still gonna play this out and see if they really need only one nap. I love the troublesome tots.com website on all things sleep related and there's an article on dropping naps son it's making me think. Here's the link if you want to check it out
http://www.troublesometots.com/baby-drop-naps/