You should list your fish as spec. Sentang from Jambi/Sumatra. It’s the most sold form of our genus during the recent years. So I guess that you received them by buying them in a shop, not from a private breeder. The aquarium trade only rarely imports Parosphromenus but if they do it’s only a very few species easily to be caught in great numbers. Mostly all are called “deissneri” which is nonsense. But people have dificulties to differentiate between the different forms. All imports are wild caught, young of the last breeding period. And Sumatra is the formost exploited area as Paros are concerned. And the hitherto undescribed spec. Sentang is quantitatively speaking the most and easiest caught and therefore the most sold. Unfortunately it is hitherto undescribed. But it is obviously very near to P. bintan as you rightly suppose. We cannot say nowadays if it is identical with bintan or whether it is a subspecies or a semispecies deverloping to a good species or what else. It is reasonable to keep it apart.
Since long we want to describe the most important of the hitherto undescribed forms on our homepage (“Other forms”). But it is difficult for different reasons. Nevertheless I hope that we succeeed with the most wanted and most sold forms in the nexts months. The spec. Sentang is certainly among them.