Someone at the show realized that any nighttime soap worth its salt has to develop interesting (and usually funny) peripheral characters to spice things up. Tony D. Gardener* has always been around, but they wisely don't use him too much. He brings a different sort of amusement in his interactions with the Carringtons, since they're usually hitting us over the head with sarcasm and sophisticated references, and that kind of stuff just goes over his head. Similarly, Fallon's assistant/secretary Alison has been "around" for a season or two but only toward the end of the season do we actually get more than the usual one-sided interactions with her employer. Tony and Alison more like the "every man/woman" of the show, since you get the idea they go home at night and laugh at all the insane behavior they witness all day at work.
* I refer to Tony as "Tony D. Gardener" since they have yet to give him a last name, and Fallon usually identifies him as "Tony the Gardener" as if that's his whole first name "Tonythegardener". It reminds me of how self-centered Karen Walker of Will and Grace dehumanized her staff by referring to them by their job rather than by their name. "I asked Cook not to add onions to this soup," or "Hey, Chauffeur...who said you could make eye contact?"