I think I agree with Frakes on this one.
"To this day I do not understand 'Yesterday's Enterprise'. I do not know what the fu** happened in that episode. I'm still trying to understand it – but I liked the look.
At least him and Michael Piller admitted there were some serious plotholes involved.
I think the problem is trying to get mileage out of "Yesterday's Enterprise" and "Redemption" to justify Probert's-C. You can't because there is no room for it because if Probert's-C was the TNG-series E-C then magically substituting the Sternbach-C in the Narendra battle would've cause the Klingons to question what this mystery ship was that was destroyed there since it wasn't any ship from Starfleet.
Now, that is not anything I've been suggesting. Given the possibility that "Redemption II" relocated events of "Yesterday's Enterprise" into a parallel universe, the Sternbach-C would be the predecessor to the "D" of/in that parallel universe.
But since the ship that actually arrived back in our universe must then
have come from a parallel one (i.e. one where another Tasha Yar had equally not died on Vagra II) its actual configuration would be conjectural, but we have the conference lounge wall of our "D" that tells us about the "C" that disappeared and the one of the "E" that tells us which one reappeared (apparently, after the Federation and the Romulans started talking again to each other so the Federation could finally learn that another "C" saved the day at Narendra III).
What the Klingons actually did know about the Federation ship that rushed to their defense remains widely unknown. Possible they heard "This is Federation starship Enterprise NCC-1701-C, received your distress call and are en route to provide assistance" and that was about it. For all we know the Klingon eyewitnesses were just "earwitnesses" after the Romulans had taken out their long range communications!
The only party that could possibly tell which ship they fought prior to its disappearance and which ship they fought that reappeared (i.e. have visual confirmation) were the Romulans.
Where it really gets interesting, IMHO, is what Picard did or did not do, after hearing Sela's account in "Redemption II".
Did he pull some strings to figure out the fate of the Enterprise-C
and learned that the "C" that reappeared was no longer the one Starfleet had assumed?
It's not before the next episode ("Darmok") we catch a short view of the conference lounge wall behind Data and can notice that it has changed.
My pet theory is still that Gul Macet pissed Picard off during "The Wounded" with some vitriolic remarks that made him want to take the sculpture wall down, but YMMV.