Check out my Ash Team
Pikachu, Dragonite, Gengar, Lucario, Sirfetch'd, Rillaboom, Tyranitar, Salamence, Flygon, Absol, Dunsparce, Latias, Rhyperior, Drapion, Lickilicky, Houndoom, Steelix, Solrock, Lunatone, Eevee, Aegislash, Aggron, Weavile, Corviknight, Aerodactyl, Alakazam
Yeah, no way this is happening, way to many Pokemon and some are just way to unrealistic, even for Ash's standards. I think we can eliminate Steelix by default (Brocks main Pokemon - which Dragonite wasn't for Iris). Too many Dragon types (Ash needs to stay the underdog against Leon). Solrock and Lunatone don't fit Ash and even if he would to get them, he would get only one, while Goh would get the other. Lickilicky i can't see happening either. I hope he is done with Kanto mons, since he has too many already, which means Aerodactyl and Alakazam are out (And so is Eevee if it doesn't evolve). I also can't see Ash getting a Houndoom, because its basically a Hellhound.
Another thing: I recently watched Ash's League match with Gladion back. The announcer said Ash has an aggressive battle style, if they keep up with that, Ash isn't getting any Pokemon that is a stationary tank, which instantly eliminates Aggron, Rhyperior and Rillaboom as well as Tyranitar to a lesser extent.
I think he gets 10/11 Pokemon tops. The rest will be filled up with reserves.