Quick points since I'm working:
1. This matchup in SC3 and SC4 was dead simple. The Sophie-esque moveset has historically been MAJORLY flawed, and Cerv could always capitalize with his own tools pretty effectively. SCV is very different, however; 3A being -16, for example, is a huge change already, not to mention the massive ramifications of the movement nerfs. And also, for the record, sc3 Cervantes was way stronger than this one. SCv Cervantes is really, really good; SC3 Cervantes was ludicrous.
2. A large part of my assessment is based on a couple of techniques very few players can do properly. Throws being i17 and 3B_2A+B being i20 (3 frame difference) means that, with a little practice and good reactions, you can fuzzy guard and defeat most conventional Cervantes mid/low mixups. You circumvent this by doing things like 1B+K~G, waiting a bit, or using shitty mids that are faster, but the net result is waiving off frame advantage in conventional mixup scenarios. Once Pyrrha realizes this, you're in a lot of trouble unless you go back to risking 1/4 life trying to get her off of you.
3. The vids Xyerith linked are old and thus aren't representative of how that matchup evolved. They oughta illustrate some of the extent to which it's a HORRIBLE thing to let Pyrrha in, but that oughta go without saying. The problem here is that there's no real way to zone in SCV. Backstep is -20 and forward step is -4: do the math. Cervantes ends up doing things like 4~2A in order to try to interrupt, which is reasonably annoying for Pyrrha, but this, too, devolves into a guessing game that's pretty well in her favor: Dash-in and block or dash-in and aGI for Pyrrha.
4. My actual matchup numbers are probably 7.5:2.5, and I base this around guess ratios. First, bear in mind that THAT DOES NOT MAKE THIS MATCH UNWINNABLE. It does, however, mean that you have to make far better decisions than the Pyrrha player if we assume perfect technique on both ends of the matchup. Here's why--generally speaking, Cervantes just has to make
more decisions, period, and one of the primary factors in SCV is how many or few real decisions you have to make in the course of a match. Pyrrha's generally running offense based on safe, tracking mids that do decent guard damage (6~44A will shut down all movement for major damage, and it's -2 on block, breaks guard, etc). A lot of the time, when she tries to attack and you block it, she's working a reverse mixup. Likewise, when she lands an attack, she has frames to keep going or, if she knocked you down, you're in the braindead wakeup blender.
Now contrast that with Cervantes. Much of his offense is zero-sum, meaning you either do damage or you receive damage. In Pyrrha's case, he's receiving a LOT of damage for attempting any low or throw that's ducked. Combine this with the fuzzy guard situation, and you're generally only landing consequential mids when you outmaneuver Pyrrha, which is damn hard because of the overall system mechanics and Pyrrha's specifically outstanding movement. And this movement necessary to set up for big damage involves risking things like 44A CH, etc, which has no real penalty for Pyrrha if she guesses incorrectly, as opposed to how Cervantes cannot discourage Pyrrha from sidestepping (apart from 2A, which is trivial damage) without risking his own lifebar.
Basically, Pyrrha can autopilot and react a TON in this match, whereas Cervantes has to take risks and make reads.
As a counterpoint, Cervantes beats O.Pyrrha up. Her slower normals and poorer movement (plus the absence of a couple of key tools) allow him to outmaneuver her and force more meaningful choices onto her. Easy peasy.
EDIT BECAUSE MATH TYPO.
-1AB is incredible risky to duck (other characters get a lot better punishment than Pyrrha)
-Cervys punishment on ducked throws is much stronger then Pyrrhas so i dont care at all, its a point for Cervy
-iGDR you should never do on block any way,its a move for combos, most of the cast gets more damage then she does again
-2K you are right of course
-66B spaced well cant be punished but i will crosscheck again this evening.
If Hates thinks this matchup is 8:2 then he has lost his mind completely. That must be a joke, especially from Hates since he should know that this Matchup in SC3 and in SC4 was much harder and Cervantes was never as strong as in this game.
I will watch the match later this day and comment, but coming to this point it seems like most people are blind to arguments so its probably a waste of time.