Dueling Works: The second and third seasons of JCA were aired alongside the animated take on The Mummy trilogy. JCA managed to get a few more seasons in than The Mummy, which was put in stasis for 5 years after two seasons.
Keep Circulating the Tapes: The only official DVD releases this series got were 3 single disc sets containing 3 episodes each, which don't even comprise the whole of Season 1, though a Season 1 set has been made but good luck finding it. A Season 2 DVD set was released in 2012, but it's out of print and a bit pricey. The first two seasons can be found on Hulu. Fortunately, the entire series can be purchased off of iTunes and Amazon Instant Video.
When Hak Foo originally debuted in the first season episode "The Dog & Piggy Show", he was voiced by Jim Cummings. After he became a regular, starting with season 2, John DiMaggio took over the role. In "Deja Vu", when Jackie relives the events of Hak's debut episode DiMaggio still voices the character.
Likewise, Julian Sands voiced Valmont, but only for seasons 1 & 2. Greg Ellis voiced him in season 3 and Andrew Abselon voiced his handful of appearances in season 4.
After originally being voiced by Corey Burton, all other appearances by Xiao Fung have him voiced by Glenn Shadix, who also voiced Tso Lan (Burton was actually never credited as Xiao Fung in any of the episodes where that character appears).
They even lampshade it. Season One had the team looking for the 12 talismans of Shendu and Season Two had them trying to prevent the unsealing of the 8 demon sorcerers. Season Three had the talismans destroyed and inhabit the animal namesake (the same magic in a new container) and season five had them looking for the artifacts of the immortals that imprisoned the 8 demon sorcerers (same elemental powers in new containers). Season four is the only completely original season with the Shadowkhan masks.
The entire main plot arcs of all five seasons follow a basic structure: Locate potentially dangerous, if not apocalyptic, magical power sealed away somewhere around the world.
Drago evaluating potential henchmen when looking for people to replace the Enforcers. The rejects (other than Valmont) showed results similar to those from when Finn tried to create his own gang.