Downstage set of legs is widest, upstage set is narrowest, ones in between follow the diagonal line from downstage to upstage on each side of centerline. Sometimes, but not always, the overhead borders do the same thing: downstage is highest, upstage is lowest.
The term comes from the Italian Renaissance to enhance the painter's "forced perspective." Pretty much ruins lighting positions, sightlines, and exposes more black velourleg than is necessary. I'm guessing this is a small company used to playing larger stages, and this is their attempt to make the stage seem more intimate.
If you thinks it's gonna hurt you, just move each set of legs onstage 1' L&R of C.L. than the next set downstage and you will have fulfilled the rider. No matter what, be prepared to rehang the legs upon the company's arrival.