If you're running Hidden Power and Baton Pass, then either you're not running Psychic (bad), you're not running Growth (extra super bad), or you're not running Morning Sun (which is one of the biggest reasons to run Espeon in the first place). Typically you're choosing one or the other.
What does Morning Sun do for you?
I think I know where all those calcs are coming from, Isa. If so, if you add the spikes damage option to the mix, the calc assumes that the opponent is being attacked on the switch-in. In this particular scenario where you'd be growthing on the switch-in, opponent's effectively only taking 6.25% damage from Spikes, since you would start dealing damage to it at 15/16 (93.75) health instead of 14/16 (87.5).+1 Espeon Hidden Power Grass vs. Tyranitar: 183-216 (45.4 - 53.5%) -- 93.6% chance to 2HKO after Spikes and Leftovers recovery
Mushroom, half the reason? I'd say it's more like 90% of the reason is for beating Raikou, the other 10% is for growth passing (and non of it is for Morning Sun). It's not the only growth passer, sure, but it's certainly also not the only recovering psychic poke.
A slower paced Espeon set that can actually be surprisingly useful is Psychic/Growth/Toxic/Morning Sun.
Common Espeon switch ins (Snorlax, TTar, Egg) all hate toxic. It can actually really bother some teams.
Scizor in gsc ou is pretty bad, let's be real here. It's only purpose is baton passing either agilities or swords dances or substitutes, which might be good on paper, but whenever scizor enters the battle it will stare down a skarmory, a steelix, a suicune or even raikou or rhydon to some extent. Baton pass is just the only thing it isn't terrible at, and everyone can see a baton pass coming from miles away. For speed and/or sub passing it is even outclassed by Jolteon.
With hidden power bug, hidden power steel and wing attack being the only "real" attack moves it can make use of it won't be able to effectively use those stat boosts and you are better off with one of the more conventional sweepers instead of the steel bug.
GSC Scizor is not great, but better than people think it is. Not every team uses a Steel Phazer, and passing SD is pretty rad. Most of my Ttar teams could be destroyed by a well-played Scizor.
Fortunately, the set of people who actually use Scizor is wholly contained within the set of terrible players, thereby precluding the "well-played" descriptor.
I feel like scizor in DPP hasn't been talked about enough, it had a crazy time with it.
Originally it was kind of uncommon, but it had a niche with its bulky SD roost quick attack set and great set of resistances. Heatran wasn't as common as it is now and scizor could set up on the majority of old school walls (see obi stall).
Then platinum came out, providing scizor with bullet punch. It seemed like everyone was using SD scizor, with all different kinds of offensive and defensive EV spreads. But everyone came to the unanimous decision that too many things resist bullet punch. On came the rise of choice band scizor, something which no one saw coming. This was mainly for its revenge killing capabilities as it handled a lot of scary threats in the metagame. Such as latias, salamence and gengar; as well as older threats like weavile, alakazam and cresselia.
SD scizor was still popular especially the iron plate set which helped disguised the set. The other big change to scizor which is often under looked is the addition of superpower, an excellent coversge move for the pokemon most notably ohking heatran and magnezone on the switch in.
Scizor was so popular that offensive pokemon like gengar and latias would run HP fire, solely for scizor and nothing else really. Sacrificing both a moveslot and a speed iv, not having max speed is a big deal for most of these pokes.
Now I feel like CB scizor is mainly used for its trapping capabilities combined with the most powerful u-turn in the game. SD scizor remains a solid set and there is still not one 'stand out' EV spread for it, especially the defensive sets.