Lin Feng had eight direct disciples under his wing as of current. It would not be too excessive if he took in Big Luo as well. Lin Feng himself was not too concerned about the number of disciples he had. Even if he did care about traditional limits, nine was the appropriate number and he had yet to mentor a ninth and final one.
As for the negative effects from the news of him taking in Big Luo as a disciple spreading throughout the Divine Lands, which could possibly lead to further conflicts and furors between the human and demon races, Lin Feng was not too particularly concerned as well. Everything had pros and cons, but whether one was more than the other depended entirely on handling the matter afterwards and personal capability.