Twin dads: how do you handle two toddlers when one wakes the other every single night?

Zoya and Zain are two years old. They share a room because we have two rooms in total. Zoya wakes at 2 am like clockwork, and within four minutes Zain is also up, and then it is a 90 minute production to get both down again. We have tried separate cots, white noise, a later dinner, an earlier dinner, my wife sleeping in their room. Every solution works for three days and then the schedule reinvents itself. I work nights so my wife handles most of it and she is at the end of her rope. Parents of twins, what worked for you? Did they eventually just sleep through, or did you do something specific that finally made it click?