When a non fan or main of a Champion reworks them it is incredibly apparent and vice versa
Examples of clear Mains reworking them:

Their core identities only got better and even tho they got weaker in some aspects their overall gameplay got drastically improved and they are way more fun to play for not just mains but everyone
Examples when someone with no understanding reworks a Champion:

Why is this difference apparent and important?
When a Champion is reworked by a fan/main they are made a better and healthier version of what mains/fans already saw. They became what they really should have been from the start!
GP mains loved Ravenous and Shiv to clear waves and collect the big bucks. They doubled down on that with a new gameplay idea that didn't feel forced, it felt natural. "Oh yeah GP would always do that right on woo!"
Ashe would totally fire mad arrows at you and have consistent damage, that makes sense as an Ashe player wow cool woo
When a Champion is reworked by a non fan/main they are turned into a new gameplay idea that feels forced specifically onto them** just for the sake of arbitrary variety/diversity**
Garen spins slightly more and has % health damage for some reason? ok i guess?
Mordekaiser loses his identity as a spammy mage bruiser and becomes an AD Tanky Melee ADC replacement...uh what?
Skarner is known as the Kidnapping Racecar scorpion so obviously just make him Dominion and remove a lot of his MS mechanics. To quote Scarra's keyboard: QQQQQQQQQ
Skarner is not a Juggernaut like Morde/Darius/Garen, he was always played for being a stabby racecar
Mordekaiser is not a carry nor is he a duo laner and it doesn't make much sense for him to do that, but his R stealing ghosts of monsters MAKES SO MUCH SENSE WOW PLS RIOT
Garen does more than just go "hey its a villain i do not like," you probably needed to give him something similar to Darius passive new mechanic.
Random idea for Garen since he seems the most off on these reworks
Give him new resource called DEMACIA that generates by taking damage, and he can empower any of his abilities by using his new found patriotism. New effect on Q? you got it bb. New effect on W? wow cool bruh. New effect on E? spintowin.jpeg. Possibly even allow him to spend the points on his R to get the Anti-Villainy effect.
Anyway, this was me rambling about clear misunderstandings by Riot on how these 3 champs work or why they are loved by fans/mains. It's so weird because they nailed Darius, Fiora and GP so perfectly. So odd. What happened Riot?
. What did she get again?
Hi, Ashe!
Shoots Arrow

or 
late game hyper scaling and turn him into a early/mid game bruiser who is pretty useless. When I started this game I would not have believed it.. but after watching Morde turn from a late game ap carry, into a early game ap bruiser, and now a weird adc support... thing..? No champion is truly safe.
and
have not seen similar changes despite also having level 1 transform abilities.
?