T-Max developer is OK. The choice of developer won't have a major impact here. I use T-Max dev for Delta 3200.(posted 9270 days ago)No, the problem is rather deeper. It is concerned, as Lot said, with your editor's expectations. I have seen some wonderful dance photography, and they were pin-sharp, but they used lots of light.
When I photograph musicians, I sometimes like some blur in the hands on the instrument, it shows life, action, whatever. You might try to persuade your editor of the merits of this.
You use a tripod. Have you tried panning (probably hand-held), following the movements of the head of one of the dancers? At least the head would be sharp. Or similarly, pan with a foot, or a hand.
But that is just making a virtue of a necessity. I fear we have a stalemate. Resignation may indeed be the best option.