Well as we saw with Bulbasaur, Squirtle and Charizard, Ash having all 3 starters can be done and it could be brilliant as well. The Kanto starters are the ones everyone remembers. I think the writers did a really great job with those 3. They each had their own personalities and focus and you could really get the sense that Ash had a strong bond with them. So the writers did a great job there especially with Charizard. Bulbasaur and Squirtle didn't evolve but they didn't have to. People fell so in love with Bulbasaur and Squirtle that you never heard people say, "why didn't Ash make them evolve?!" I guess you heard some of that but not much. Now I didn't watch Johto in awhile so I won't judge but the reason his Johto Pokemon were handled poorly is probably because Ash still had his Kanto starters with him. I mean in THE JOHTO SEASON, it was Ash's Kanto Pokemon Charizard that won Ash his first badge, last badge, beat Gary, battled Entei and fought with Blaziken. I loved that honestly because I am such a Charizard fan so of course I didn't mind it. But when you have the writers giving Charizard the big wins in Johto, it takes something away from his Johto Pokemon. It makes it look like the writers didn't care about them as much as Charizard which I'm sure they cared for Charizard way more. But the point is with a series as long as Johto, Ash having 3 starter Pokemon could work if the writers did their job. Like I said, I didn't see Johto in awhile so I won't really say if the writers did their job or not. Although I will say it is kinda strange how Cyndaquill ended up evolving in Sinnoh. They had time to evolve him in Johto. Little strange to me. No big deal. But Cyndaquill evolving is a huge thing. It would have been awesome if it happened in Johto and then Quilava was a force in the Johto League. I mean if the writers are gonna evolve Ash's Pokemon especially a starter Pokemon like Cyndaquill, it makes sense for it to be in Johto since Ash is with Quilava. Quilava appeared in Sinnoh but at that point, Ash didn't travel with Quilava so we didn't really get to have to many episodes with Quilava like we did with Bayleef since Quilava quickly got sent back to Oak after he battled in the Sinnoh League and Quilava didn't even get to battle against Tobias.