Winter in Fixing RWBY, is not Winter. She's been altered from canon so strongly that I couldn't come up with a central thesis for her differences beyond this. Sure her personality may superficially resemble her canon counterpart's, but her actions and arc are so different she just isn't Winter anymore
First, she's a shitty mentor to Weiss in this universe. In canon, Winter explains to Weiss that your semblance is like a muscle and needs training to be effective, the implication being that Weiss never tried hard enough on summoning due to not getting it quickly. In FRWBY the Schnee's summons are still somewhat sentient and they outright refuse to be used by Weiss. Winter can't even give any real advice to fix her problem it amounts to "IDK just figure it out"
In canon when Weiss tells Winter that her card has been frozen by Jacques, Winter encourages her to stay independent of him and to forge her own path in the world. In FRWBY, she tells her to "appease the enemy" and call him so she could use his money. Yay a "smart, pragmatic" change that destroys Winter as a character by her second scene
The Volume 5 character shorts gives us a contrast between Yang and Winter as elder siblings. Winter: "I'm not always going to be around to save you Weiss." Yang: "I've always got your back, sis." This comes back in the Volume 8 finale where Yang sacrificed herself to save Ruby from Neo, while Winter was too late to save Weiss from falling into the void. FRWBY completely removed all the character shorts past the Pre-V1 ones, completely destroying this dynamic. FRWBYV8 hasn't happened yet, but if Celtic keeps the finale in any way similar to canon here it will just be weaker than canon
In canon Winter is highly protective of Weiss whenever she is around. She may take the tough love approach to make sure Weiss is prepared as a Huntress, but her care is obvious. In canon, she orders Weiss and the rest of the main cast to be freed of their cuffs within seconds of seeing Weiss under arrest. In FRWBY, she has an entire conversation with the main cast and doesn't take off their cuffs until they're done talking. Not Qrow though because haha funny sitcom archnemesis amirite
Winter in canon is one of two members of Ironwood's inner circle that we see go against the grain of Atlas' military culture, the other being Marrow. A consistent thing that the Ace-Ops repeat over and over is that they're unfeeling disposable cogs in the machine that is the Atlas military, even if they don't really feel that way about themselves. It plays into Ironwood's beliefs that throwing away your humanity is the answer to beating Salem, and obviously this runs counter to RWBY's themes of individuality and making choices for yourself
Winter though has people that she can be open about her feelings with, Weiss who she clearly loves, and Jacques who simply hearing him speak wears away at her cold and calm facade. But she still has that Atlas military culture ingrained into her which is why her arc is eventually turning to the heroes' side. We see Winter and Marrow struggling against their conflicting feelings between what they believe is right as Ironwood makes increasingly more monstrous decisions over the course of the Atlas arc
In FRWBY Winter almost seems to be against Ironwood from before the start of the Atlas arc. She's Robyn's inside woman to anything happening involving Ironwood and leaking intel to her, even before V7 started she's been Robyn's "little bird." Although it's completely unclear if she ever told Robyn about Salem, probably not. She has clear moral problems with Ironwood's treatment of Fria. When Ironwood shoots Ruby off of Atlas she's clearly horrified by the action
In canon Winter was slated to be Ironwood's maiden. Given her position as his second in command, her status as the best fighter in the Atlas military, and strong loyalty to the General it makes a lot of sense. In FRWBY, Penny was Ironwood's maiden choice. What? Assuming that Winter still becomes the next winter maiden in V8 this weakens the layered tragedy of FINALLY getting the power she was promised, at the cost of losing a dear friend in Penny
Speaking of Penny, any dynamic Winter and Penny have in canon is completely removed here. Given the drastic shift in direction the entire Atlas arc has in FRWBY, and for this topic Winter and Penny's direction, the "human machine vs machine human" dynamic they had has been completely erased. Hell they only share a single VERY brief scene before the volume's climax while Penny is getting a maintenance checkup, and there's still basically no dynamic or theming between them
Even Winter, the person that's the most in Weiss' corner, gives her a bit of shit for running away from home. Not as much as the rest of the family, but still. Winter concocts a plan with Weiss to help her to try connecting with Whitley, but fuck this entire Whitley storyline
In canon Winter is the Flight response to the trauma inflicted on her family by Jacques' abuse. When Jacques confronts Ironwood outside the run-down Dust mine, Winter is nowhere to be seen until after he leaves. During the council meeting just hearing him speak, not even directed at her, it stresses her out and irritates her to the point that she breaks her usual calm facade
In FRWBY, this aspect of her has been HEAVILY weakened to the point of being almost nonexistent. When Jacques first arrives trying to force Weiss back home Winter is just sitting at the table. Even speaks directly to him for a bit
During a meeting between Ironwood, Jacques, Camilla and Sleet, and a bunch of business tycoons, Winter Qrow and Clover are also here with Ironwood. The only time Winter is in any way relevant is when Camilla makes an offer to her to become the next Atlas General due to the rest of the council losing all faith in Ironwood. This would have her work with Jacques since he's also their candidate to take Ironwood's other council seat. While Winter is uncomfortable at the prospect, she still considers it since it would effectively give Ironwood a voice at the Atlas council. No real focus was given to her in this meeting and her feelings on Jacques, entirely in favor of Ironwood
Due to Ironwood announcing at the meeting that he'll instate himself as dictator of Atlas (more on that in his dedicated post), Winter gives Robyn a recording she made of the meeting to air his dirty laundry
During the volume's climax Winter and Penny are sent to Atlas' vault where they meet Cinder. The fight was completely overhauled due to Fria also being an active participant the entire time, and due to this Winter isn't beaten within an inch of her life by Cinder. Unlike in canon there's no dialogue or dynamic between anybody at play, it's just a fight. Keep in mind that Celtic HAS given characters mid-fight banter earlier in this project. But not here
Our final scene of Winter is her putting a hand on Penny's shoulder while at Ironwood's office as the Atlas military is about to invade Mantle to enact martial law
Even from a character design standpoint Celtic messed up on Winter. In canon her bun changing to a ponytail in Volume 8 is a visual sign of her doubts on Ironwood and her eventual turn against him, as opposed to the extremely tight bun she had her hair in prior. FRWBY has her keep the bun the entire time even though she's been rewritten to be more against Ironwood a LOT earlier than she was in canon
Despite the huge, colossal, massive, overloaded, overbloated, overhauled, eight and a half hour long Volume 7 of Fixing RWBY, Celtic could barely spare any time for Winter. She has so little screen time relative to the gargantuan length of the video. Despite this little screen time, Celtic completely overhauled her character. She's completely unrecognizable from her canon counterpart. Everything and I mean EVERYTHING she had going on has either been completely altered, heavily weakened, or removed altogether. At least when Celtic turned Vernal into an OC he had the transparency to give her a completely new design. This just isn't Winter, at any level