Was Shrek Academy's slap in the face a case of dumbing the characters down?
First, when Yu Dashi saw Tang San and the others deliberately beaten into serious injury, he would complain to the tournament committee, whether on emotional or rational grounds.
After all, this academy's rule was to bully the weak and fear the strong. With Flender and Liu Erlong there, Yu Xiaogang would certainly have the confidence to confront Skywater Academy, which had no Title Douluo.
Then, naturally, he got slapped in the face.
Finally, I specifically added that Shui Yuewu had withdrawn her Martial Soul when she kicked Yu Xiaogang.
So, given Liu Erlong's "love" for Yu Dashi and her fiery temper, when she saw a woman without any Soul Rings hit her brother, she was absolutely going to rush forward to retaliate.
The outcome spoke for itself.
I think it was pretty reasonable. If you insist on calling it dumbing them down, there was a tiny bit of that, but it wasn't particularly outrageous, was it?