I thought that in the case of tamers (not the season but the concept), they were supposed to have more. That's how it is in Xros Wars. I RP a lot and I also write a lot, and through my writing activities I've come to distinguish between different "types" of Human partners, and even some sub-types for those types.
DigiDestined: Two types. One with crest (Adventure 01/02) and one without (Savers/Data Squad). The former uses a crest to make their Digimon pals achieve higher levels of power, while the latter charges DigiSoul/Digimon Natural Ability to make them digivolve. I always imgaine DigiSoul to be a stronger-yet-easier-to-use version of the crest method. In that the raw emotions are what give the Digimon power, not specific traits as with the crests.
Tamer: The most Pokemon trainer-like type of human partner, I imagine tamers to be, well, tamers. They "tame" "wild" Digimon and create their own personal army that way. Obviously, they would lack bonds as deep as the former type since they have so many Digimon partners. A sub-type of a Tamer would be a Xros user. Seen in, well, Xros.
Shapeshifter: Seen in Frontier. Everyone knows about it already so I don't need to go on.
That's along the lines of my gripe with the Pokemon RPG series. Pokemon as a whole, really. The stagnation. For a franchise that goes on and on about friendship and raising Pokemon the right way, the lack of Digimon World-esque games speaks louder than anything else, as far as I'm concerned. You would think Pokemon would be the first game with a pet-raising video game but no. Digimon does that instead. Even though Pokemon trainers have more Pokemon than Digidestined do Digimon, the latter had a pet-raising aspect/game. Isn't that funny? Meanwhile, Pokemon continues to mass-assemble the same stuff year after year. Now Pokemon is trying to jump on the bandwagon with that mega evolution business. No. It's too late. You had your chance, Nintendo, and you failed. FAILED!
Could you link me to some manga, please?