The Power Pack was jointly headed by Julie Power and Franklin Richards (yes, the son of Reed and Susan Richards, two of the original founding members of the Fantastic Four). As the son of Tony Stark (even had Tony not been Iron Man) Harry would likely have still run into Franklin Richards (if I'm not mistaken, at this point in the timeline, neither Reed or Sue is aware that Tony is, in fact, Iron Man) as Reed Richards and Tony Stark (along with both Victor Von Doom and Otto Octavius) are well-known scientists and inventors. (Dr. Octavius is, if I recall correctly about this point in the timeline, teaching at ESU; among his students is Peter Parker. The accident that created Doc Ock hasn't happened yet.) Reed and Victor are ESU alumni (and brain rivals while at ESU; that's according to Victor himself), as is Tony Stark; Richards and Stark both recruit at ESU (both have their first encounters with Peter Parker there, and neither is initially related to Spider-Man; Parker had applied for internships with Reed and with Stark Enterprises).
Cassandra Webb is one of the most shadowy figures in the Marvel universe (and she's no more evil than Uatu the Watcher, and far less is known of him), despite her encounters with most of the heroes (and no small number of the villains) of said universe. She's at least as alien as Stephen Strange (or Agatha Harkness) from either a muggle OR magical POV; Strange himself admits to being baffled by her. Strange at least suspects (as does Reed Richards) that she is at least complicit in the grey turn of Victor Von Doom, especially while ruler of Latveria (which had a reputation as bleak as Bulgaria or Genosha prior to said turn).