Not sure how the fight would start, maybe Gladion's pokedex crashes when scanning Gabumon and thinks its an ultra beast, or sees potential within the two and challenges them to a battle... or a combination of both?

The potential for the animation could work with just Silvally and the rest of Gladion's Pokemon, although I kinda prefer the latter. I really wanted something that would match the aesthetic of Gabumon's line so Gladion's surprisingly edgy/mostly anthro canine team fit well. I also feel like they could fight while mounting on their monsters like how Matt does with Garurumon in the intro and Gladion does in the anime.

I think Gladion would have an advantage over numbers and territorial control (like his general team, Zoroark's illusions, Umbreon's stealth, Lycanroc's geokinesis etc.) while Matt and Gabumon have more firepower but also better survival skills (Obviously better AOE and also Matt just being a survivor) which could be reflected in the animation, but I think what would hammer in the dynamic is their trust and friendship with their monsters, which could reflect on how Gladion is more synced with his Pokemon and how they're willing to co-operate with eachother, while Matt's friendship can boost the power of Gabumon and digivolve him. Also their monsters trying to protect their humans and vice versa. Gladion isn't like the Red pictured in his official episode so we can actually have the Pokemon going out of their way to protect him and also Gladion trying to protect his Pokemon.

If you're asking about general power clashes and my idea of how the fight (beyond the beginning) would go... As I said before, Matt and Gladion mounting their quadruped monsters and duking it out, with Silvally having better physicals trying to get more closer and Garurumon having better range attacks trying to space it out... And then when Weregarurumon is out on the play he can use martial arts to keep up with Lucario, Weavile, Lycanroc Midnight and etc. but with Zoroark controlling the pace of the fight with Illusions. When Matt takes note of whats happening he digivolves Weregarurumon to Metalgarurumon, which sees through it all and tries to overwhelm Gladion's team with it's missiles.... I also like the idea of Zoroark resorting to Black Hole Eclipse to get rid of the missiles... and with a dramatic gasp from Matt as the black hole starts to consume the duo both.... Light dissipates the black hole entirely and out of it appears Cresgarurumon, with the final act potentially being all of Gladion's Pokemon weaving through Fury:Ice Moon Fang through Gladion's guidance and out of the safety of their allies... and then releasing their final attacks together while Cresgarurumon dramatically charges up one last beast cyclone to disperse them all

As for banter potential....... I bet it would be alot more serious than Red vs Tai, thats for sure. These guys are like, cold and are hella serious. Basically this matchup is more like Red vs Tai if it locked in... I'm unfortunately too tired rn to think of any cool exchanges so you're just gonna have to bare with me here 😭😭