Now we're starting the Eight Geniuses arc. Things are about to get rowdy~
Feng Ji (Pang Ji, historically) was, as anyone can tell here, an advisor to Yuan Shao. However, he didn't amount to much, and was pretty quickly killed off in a negotiation between Yuan Tan and Yuan Shang. Such a shame that the esteemed Yuan family went down crumbled by its own hubris...
We also get our first look at Yan Liang, the mighty warrior known for his biggest exploit... getting killed by Guan Yu, lol. Historically, he was a supposedly high-ranking officer that had no real battle merits, and was considered a frivolous general. IIRC he was "buffed" in the RotK novel in order to make Guan Yu look better.
Professor Water Mirror is also known as Sima Hui, and is famous for having been the teacher of Zhuge Liang, among others. It's unclear whether or not Pang Tong was actually a student, or someone who just happened to know Hui. Now, no spoilers here, but I'm sure it doesn't take much to guess at least 2 names among the 8 geniuses lol. Yuan Fang (a.k.a. Mr. No-Match), introduced in chapter 11, is another one of the 8.
Historically, Prof. WM wasn't so arrogant, he was actually known to be super pleasant - his nickname was "Mr. Yes" or "Mr. Good" depending on how you translate it