My understanding of the concept was that it was something like multiple channels of data being sent along the same wire. So long as the frequencies are the right kind of different they’ll essentially exist completely independent of each other.
Maybe this requires a minimum of two time dimensions so that the variance can result in the different beings following time along different “tracks”?
I took Troi’s awareness of the beings to be a result of the intermittent overlapping bits of time where they did overlap. Like, it happened too quickly to perceive visually, but enough for the empath to have something to pick up on.