So I just discovered something absolutely adorable about the Pokemon Ingo and Emmet use.
When it comes to what Emmet and Ingo's starter Pokemon could have possibly been, there isn't really much of a consensus. Probably the most popular idea is that Ingo started with a Litwick and Emmet started with Tynamo. However I want to make an alternative suggestion. They each started out with a Klink of their own!
So hear me out a little. I don't know how well known this is, but Ingo shares his Pokemon with Emmet.
When you look at them side by side, same species, same natures, same moves, same stat distributions. Hell, even their held items are the same! These two Excadrill, Haxorus, and Chandelure are identical which leads me to believe that these are actually the exact same Pokemon. So isn't that nice! They share! And I think that in-universe this makes sense. Since each of their teams on the Singles and Doubles circuits seemingly need to all be unique Pokemon (for that battling format), that means that Ingo would have 6 Pokemon to care for while Emmet would need to take care of a minimum of 8 Pokemon. So it just lightens Emmet's load if Ingo lets his brother use his Pokemon. And it also opens things up so that he can use different Pokemon for the Multi battle circuits! With this in mind it was probably better that Ingo got yote into the past and not Emmet since Emmet knows how to use and therefore probably how to take care of Ingo's Pokemon where the reverse may not be true...
However there is one outlier! One Pokemon that both Ingo and Emmet use but that doesn't seem to be the exact same Pokemon!
Their Klinklangs are different!
Ingo's Klinklang has a Physical Attacking build while Emmet's is more defensive and focused on Special Attack! Unlike every other Pokemon they share, these two aren't identical!
But the icing on the cake is what Klinklang's Special Abilities are. Discluding the Hidden Abilities, Klinklang's Special Abilities are Plus and Minus. For the uninitiated, these two Special Abilities are related but basically do the same thing.
(Minus is literally the same, except replace any instance of 'plus' with 'minus' and vice versa.)
Klinklang as a Pokemon is at its best when it's working alongside another Klinklang (or any other Pokemon with Plus or Minus but shhhh!) because together, they boost one another's special attack! Klinklang as a Pokemon has cooperation baked into its very blood! And it's just very sweet that Ingo has gone along with this strategy to give Emmet the chance to shine and blast their opponents with one hell of a Flash Cannon! It would almost make up for how Ingo has a 50% chance of absolutely destroying Emmet's Elektross with Mold Breaker Haxorus in any given Super Multi battle! If we actually got to see this strategy actually play out within the games, that is... Because while all of this is so perfectly set up and would be beautiful to actually see play out, they can never be fought against in a way where the two are each using their own Klinklangs... Which is practically a crime!
However I do like to think that they use this strategy when casually battling outside of the Battle Subway. And I think that it would be perfect if they've actually been using this strategy since they were kids. They're just a lot stronger together than they are apart, so they make certain to stick together! And these Pokemon would be fantastic at demonstrating that!