After reading all of this I've decided to give CIO anther chance. I decided that it's a new year so let's change something.
Yesterday was day 1. I pretty much tried to keep your schedule.
Nap#1 : 9.30am to whenever they wake up. It was about 11am.
Nap#2 : 1pm to whenever they wake up. it was about 2-2.30pm.
And then I wouldn't let them sleep for nothing. One even fell asleep for a second standing up and fell down and hit his head ((( So I finally settled them down in their crib at 7.30pm. There was a lot of playing and screaming and throwing their pacifiers all over... I gave in at 8pm(only because they are still recovering from a cold and I didn't want them congested). They all fell asleep in the arms within 5 minutes.
Today we all wake up at 5am, they wouldn't fall back asleep! So we got up and I wouldn't let them sleep will 9am, two of them knocked out in the crib after a little crying, one wouldn't stop at all ( he was turning purple) so I gave it and he fell asleep in his stroller withing minutes.
I can't take out the multiples factor because we live in a two bedrooms apt, they'll have learn to fall asleep in their crib all together. I really hope this works.