There's no such thing at all. Don't let someone tell you otherwise.
No DO school has a prestige factor above any other school, especially not in the larger medical and scientific community. If you're applying ACGME for residency, a DO is a DO and your school matters zero. It's not like MD schools in any way, shape, or form. For competitive AOA residencies, it's board scores + your away rotations, not your school name in any way.
One way to judge schools is by quality of rotations. Is the school new with really small associated hospitals that require travel or does the school have a solid core rotation set up? How expensive is the school? Those are some things that matter. Outside of that, the DO world is highly, highly individual.
This gets asked repeatedly on these forums so we should just dispel it now. No one cares if you went to DMU outside of DOs that went to DMU. Go ask an academic attending with 2 fellowships at a high ranked program if you'd be more competitive in the future for residency, a job, or fellowship if you choose AZCOM vs PCOM. He'll have no idea what you're talking about.