With what Serena is doing I don't think there's a particular need for her to fill out her team, to me it wouldn't be surprising if she ends the series with her current three - of course with Eevee as a Sylveon. She has expressed an interest in Meowstic back in like XY045 but that could just be thrown under the carpet if they want.
Regarding Ash and multiple typings, his Sinnoh team had three Ground-types on it, Torterra, Gliscor and Gible. Not all of them were there at the same time, though. If I remember correctly he caught Gible after Gliscor went for training? (Correct me if I'm wrong). Unlike this Sinnoh similarity (heh), the three Flying-types he has in Kalos don't share a common weakness like getting destroyed by Ice. It's not as bad as people make it out to be. While I'd probably find it odd if he ends up at the Kalos League with his current and fully evolved five, I guess that would just add weight for him bringing back his older 'mons for it, which I'd be more than happy with. I guess they'd be counting Goodra as the sixth in that case?
Can't say I'd feel the same way about Charizard taking the sixth slot, though. I think that's stretching it a little. Swapping Talonflame for Charizard? Firstly, he'd need a full team for that to make sense, and secondly, DON'T YOU DARE TOUCH THAT MAJESTIC THING. *raises fists*
Regarding Ash and multiple typings, his Sinnoh team had three Ground-types on it, Torterra, Gliscor and Gible. Not all of them were there at the same time, though. If I remember correctly he caught Gible after Gliscor went for training? (Correct me if I'm wrong). Unlike this Sinnoh similarity (heh), the three Flying-types he has in Kalos don't share a common weakness like getting destroyed by Ice. It's not as bad as people make it out to be. While I'd probably find it odd if he ends up at the Kalos League with his current and fully evolved five, I guess that would just add weight for him bringing back his older 'mons for it, which I'd be more than happy with. I guess they'd be counting Goodra as the sixth in that case?
Can't say I'd feel the same way about Charizard taking the sixth slot, though. I think that's stretching it a little. Swapping Talonflame for Charizard? Firstly, he'd need a full team for that to make sense, and secondly, DON'T YOU DARE TOUCH THAT MAJESTIC THING. *raises fists*