I think the zz plant will tolerate it as dry as snake plant needs to be, and both will tolerate low-medium light. I'm not sure of the peperomia.

Sounds fine to me, especially if the alternative would be to put them in separate pots next to each other. All 3 are easy to repot, which you'd want to do again in the future anyway, but especially if something starts growing fast enough to be a bully later.

When plants are grouped, the more thirsty plants help keep the others from staying moist too long.

So, since you think its fine for them all to go in the same pot, please walk me through the process. Should I put rocks on the bottom and then succulent soil and then the plants? Does that sound right to you?

Thanks!

Skip the rocks & it should go well! If you have a 2nd pair of hands to help, it's so much easier to have another person hold 3 plants upright while you finish filling the pot. When finished, the soil should be at the same level on each plants' stems as it was before, not lower or higher. If plants still don't want to stand up after group-potting, those rocks could come in handy then, to prop the stems on soil surface, if they are not as small as gravel/pebbles. Baseball size rocks are usually good for that.

Perfect. That's exactly what I will do. Thanks!