Goku, krillin, tien, and yamcha(pre-Raditz) go up against the eight digidestined and their partners. Who ever puts the other team down for 10 seconds wins. The z fighters are going avoid harming the children unless that becomes their only option. The battle field is where greymon fought shellmon.
I think if they start anywhere under Ultimate level, they're done for. Rookie is their basic level, and was basically how they stayed so the digidestined wouldn't be walking around with giant monsters always trashing the scenery. After the first season or two, though, their Champion levels were basically jobbing to keep suspense until they digivolved again.
__________________ -"My internet is currently so bad I'm time traveling. Don't worry about it."
-"You have the best problems, Scenario. You really do. haermm"
Only Agumon and Garurumon were able to reach Mega, though. Everyone would be better off at Ultimate. It's hard to see the fighters not pasting them before even getting a chance to digivolve.
__________________ -"My internet is currently so bad I'm time traveling. Don't worry about it."
-"You have the best problems, Scenario. You really do. haermm"
Physically Wargreymon and Metalgarumon would rape the shit out of the DB team, being capable of punting skyscrapers and using them as projectile weapons.
I dunno if they have the durability to withstand their ki attacks though.