This is more of a comment,
There is every evidence that there really is no
problem with having a
Newtonian disk, with or without
a
dark matter halo and without MOND.
Dark matter haloes were introduced in the 1970's
to explain the stability of Newtonian disks
but if you do a full hydro code (this is a piece of software that simulates the dynamics of a large number of particles by solving the hydrodyanmical equations of motion for the gas whilst also including gravity and collisionless matter such as dark matter. The codes accuracy depends very much on the number of particles that are simulated, in the most modern codes circa 2000 only a few million particles can be simulated. The hope is that this is enough to begin to show the dynamics of real objects galactic sized objects. These objects usually contain many orders of magnitude of particles than can be simulated. An analogy would be attempting to model the Atlantic using a basin of water.) which follows collisons accuratly then you can have a stable disk without
a halo. (it was later noted that halos explained
the rotation curves of disk galaxies)
(see disk galaxy)