Okay, time to at least sort of update.
First, I'm seriously considering dropping Magnemite to Mid, some really good points were brought up. On the fence about it overall though...
I added Slowbro to High, not really sure what to do with Slowking. Is it different enough to be Mid?
I held off on Growlithe and Staryu until we figure out just how we should handle stone evolutions. I'm a little biased toward them, admittedly, as I've always been the type to go out of my way to get things like that (I like the Pokeathlon, see Round 3/4 of the Orange League for proof) but I admit they're time-consuming. Same for Voltorb Flip, though I'm a little weird in being willing to go through that for things like Staryu.
There's a lot of odd quirks in HGSS that really do need discussion before decisions are quickly made and I'm willing to have this take a while (which it will).
Meanwhile, sure, we'll consider Kanto matchups, that seems fine to me considering HGSS has some good stuff post-E4. Actually, a lot of good stuff.
As a last note, I'd like maybe another word on Miltank from someone new just for confirmation, I'm really leaning high.
Edit: Can we talk about whether to split mid? We have three options.
1. Keep it as is.
2. Split to Upper Mid and Lower Mid.
3. Split to Upper Mid, Mid, and Lower Mid.
I'm fine with any of the three, honestly. I just worry Mid will get very crowded as is.
C&C work: 34 done, 2 partly done, finished 4th gen moveset errors