So it was unclear to me if two phases are available at the panel. Then you could connect 10x 15A circuits to phase L1 and other 10x 15A circuits to phase L2.
You would have power capacity for 14 rigs in 14 circuits.
6 circuits would remain un-used because the panel is maxxed.
Maybe I should drop out from the conversation so that I don't mess this any more.

The ANSI standard world is a bit weird to me.