Do you have an example of a good mock up?
This series is a good one
https://www.youtube.com/watch?v=Ig_jHL18NWs
Which is before the first balance update so it's referencing that specifically, but the points are still valid there.
There's no one forcing them to use the exact PoGO stats. They could change things how they want to work well for their own game. Something like
Butterfree could be made useful in this game with a buff, because right now Pokemon that were only good for prestiging will be more useless than ever. And I'm not saying they should all be Dragonite range, but it would be nice it it was a lot more viable to get them about the 2200 ish range so that we can see more variety up there.
The balance in this game isn't even entirely comparable to the mainline games despite the fact that they use mainline stats, because of how special and normal stats are combined into one stat, how pogo stats are converted into CP, and the ways in which it weights things. The way PoGO stats are converted goes like -- Mainline game base stats - conversion formula - pogo base stats -conversion formula - CP. In some cases CP isn't even a good indicator of how powerful a pokemon actual is because of the way the formula is...
...But I just realized actual CP values don't matter much anymore since things aren't sorted by CP. Though, if they're still planning on using it in the game as they are, they should better representative.
I'll give you the main problem with both formulas.
PoGO base stats are what determines how strong a Pokemon actually is in this game. The problem with the conversion there is it favors Pokemon who excel in either a special or normal stat. To be more clear, if a Pokemon has an abysmal special defense, but a super high defense, it will get nearly all the benefit from just excelling in that one stat, and the low stat will only account for 1/8th of influence on the base PoGO defense stat. Which means that Pokemon that are traditionally more balanced in both stats get shafted hard, and of course, Pokemon that excel in both stats are good to go. Same for attack. In the mainline games, Pokemon with a more balanced defense stat in the moderate ranges worked much better than they do in PoGO.
The issue with the CP conversion formula is that it, for whatever reason, heavily priorities attack over defense. Not to mention pretty much shafts speed too. Steelix is a good candidate for a Pokemon that is shafted by BOTH formulas, especially when compared to Rhydon, who has a notably lower stat score in the mainline games. And then see their max CP in PoGO: 2439 vs 3300