Okay, I fucking hate when someone says they want following pokemon in the next game.
>but, muh opinions
No, Fuck you.
It's a bad idea, and no one fucking considers the reality of the idea.
>Oh, hey, it worked in HGSS, you know, 2D games. It should definitely seamlessly transition over to 3D without a hitch.
In 2D games, clipping is very easy to avoid even if you have a large set of things in a varied set of environments that have to avoid doing so, ALSO it's less annoying when it does happen. HOWEVER COMMA In 3D games, clipping is almost impossible to avoid if you give the player enough freedom. How does this affect following Pokemon? Well, in HGSS, even though all the Pokemon were generally different shapes and sizes all of them interacted normally enough with the environment to ensure immersion was held. Also, most pokemon fit within a fairly small predefined sprite size. In 3D, all those different pokemon would be constantly clipping through trees, trainers, obstacles, you name it. If the pokemon were to battle scale, most pokemon you have by the end of this game would have this issue. So, instead of adding immersion, it would actually take it away.
Basically, it's not just a matter of making pokemon follow you. It's a matter of making it look good in a complex and claustrophobic 3d environment. It's not that it's impossible; it's just unlikely that GF will be up to the challenge for something that barely affects game play and that they could totally go without.