It is not deficient in dark matter. It is 100% perfectly natural just the way that it is. “There is no theory that predicted these types of galaxies.” This proves that scientists get it 100% wrong.
Truth: reality is what it is. Human theories and equations do not explain reality adequately. What needs to be changed, are the theories and equations!
The Universe is just fine the way that it is. Too bad scientists can’t understand it.
That's like saying no theory predicted relativity theory until Einstein came along, which proves earlier scientists got it 100% wrong.