Real Monk vs Fake Monk Just as the Buddha referred to those who achieved the goal as "My Son", I am wondering if the Buddha made any similar distinctions between monks who lived by the precepts and practiced according to the teachings, and those who were there for reasons of their own, not in line with the teachings of the Buddha?

Did he give any teachings on how to deal with monastics who abuse their position for unwholesome motivations i.e. monks amassing wealth, gaining political influence, acting as antagonists for violence.

Just as high-profile leaders in other religions have given their respective faith a tarnished reputation with shady dealings in the past, is there anything to be done to protect the dignity of the Buddhas teaching from those with less than wholesome intentions?
What you can do to protect the dignity of the Buddha's teaching is to practice the noble eightfold path to the best of your ability while the true Dhamma can still be heard in the world. There is nothing else to be done. The teaching will inevitably become corrupt and disappear from the world. There is nothing that you or anybody else in the world can do to prevent that. It's only a matter of time.

When you witness others acting in ways that dishonor the Buddha's teaching, your mind will likely respond with aversion. Identify this aversion and let go of it. If you cling to this aversion and let it be a basis for further action you're only working against yourself, even if you think that you're trying to protect the dignity of the Buddha's teaching. Mindfully recognize the impermanence of the teaching itself and use that to cultivate samvega (urgency).

Cultivate compassion towards those who, intentionally or otherwise, dishonor the Buddha's teaching. Recognize how helpless these beings are. Recognize that under different circumstances you also have the capacity to act in similar ways due to delusion. Recognize that you're just as helpless as these beings because you aren't yet free from delusion. Then work towards realizing the Dhamma in this very lifetime because you can't help anybody else without helping yourself first. Otherwise it'll be the blind leading the blind.