Here's an idea I thought of to set up the steps:
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This would be a set up for a class no more than 14 people (unless you have room to make a bigger diamond).
To make the combinations work, you would make the combinations be for 2 people. So partner 1 (on the left side of the diamond) would do the "opposite" combination of their partner who is on the right side of the diamond. Example: L-step right side, for the people on the right side of the diamond, and an L-step left, for the people on the left side of the diamond.
Everyone in the class has one step; their partner is the step directly across from them. You can make them switch steps with their partners. To make it even (so one set of partners is not traveling a longer distance; after a couple of 8 counts, everyone goes up one step and has a new partner)
Some ideas for combinations would be taking an "L-step" to the step behind you, or do a "diagonal" to the next bench.