From observation I would tend to disagree that arial roots are not different.
They do not start out fundamentally different, but as they grow the outer surface adapts to where it is.
This means that if the tip of an arial roots is guided down in to the medium the new growth will be adapted to be underneath. I do this ALL the time.
I know (from burying arial roots lots of times) that if you bury existing growth it will never look like roots that grew under the medium.
I've heard some people say that if you bury existing arial root growth it will rot. I have NOT found that to be the case, but I have always been careful to make sure it is under medium/large chunk bark so that it is still in an airy enviroment.
When I've had Phals with a very small number of roots like this I have always buried the arial roots and so far it has worked.
I would advise potting up all the good roots you have in this sort of situation.