IF, they really change the formula, I don't think the main problem would be working it out.
I think the main problem would be how it affects the metagame, e.g. whether the advantages tilt towards defense or attack.
(We experienced a similar shift towards attack when Level 50 battles are introduced)
And of course, the tilt will affect which Pokemon gets to shine, and also how you battle.
However, you can say that with the new Fairy type, new Pokemon and new movepool, a lot of things would change anyway.
Whilst it may not affect an average player, any new formula should be analyzed by hardcore people to deduce an optimized way of battling.
Talking about objectifying Pokemon, we have Mons like Alakazam and Machamp which are your sterotypical special attacker and physical attacker. That got me thinking why are special attacker generally faster than their physical counterpart? I mean is it because, for example, Alakazam's mind speed is faster than Machamp's physical speed?
That got me thinking: What if the scoop of the century is special and physical speed split?!?!?
Special attacks will utilize special speed while physical attack will utilize physical speed!
I just realized that I am a genius.
I personally associate Pokemon in-game speed with how quick their minds respond to their trainer's orders.
Otherwise it will be silly because you have Pidgeot that's supposed to fly faster than a jet plane at speed 91,
and Jynx somehow has a speed of 95, AND Alakazam at 120.
So how do the latter 2 do it? They run faster than a jet plane? They float faster than a jet plane?
Can they fly?
speed of teleport?
(Alakazam's slow moving in PBR and Stadium, so.)
Anyway, so I think it's speed of response other than speed of action, and considering Fighting Pokemon are stereotyped to be thick many times by Game Freak, that probably explains
(Well, I know you still can be slow and intelligent, but
generally.)