One thing I do with scapular wall slides, if I do use them, is I have the person have a big emphasis on terminal FLexion as well as the downward movement as well. This assures me that the person is working on upward rotation and can still get the benefits of a pec minor stretch at the bottom.
The exercise she is doing is actually a kneeling pallof press. It's primarily an abdominal exercise. I videoed that exercise to show that every single movement you do is a chance to improve how you're moving, at every joint. So, even for an ab exercise she has to be extremely cognizant of what her shoulder is doing. Otherwise she is just adding to her issue. My approach is that for someone with a serious issue, like to the degree that girl's shoulder blade was winging, I view every exercise as a therapy exercise, if that makes sense.
In her case her scap was winging during pretty much everything. From her daily life to every exercise. Thus, I tried to get her to make sure it didn't wing during anything, from her daily life to every exercise. For example, in the pallof press I would actually have her add a terminal shrug when her arms were fully extended. Adding even more work for the upward rotators.
If you're talking about the video of the cuff exercise I was actually using that for high Internal rotation. When pec major (and pec minor like you said) is tight / overactive, it can take over internal rotation from the subscapularis. Putting the elbow up high, and making sure the humerus stays nice and snug can help make sure the subscap is working and not just pec major. A strong subscap will pull the humerus posteriorly and inferiorly into the capsule. A strong subscap can then almost act as an inferior/posterior capsule stretch in itself.
I think what I'm getting at is, for the people I've worked with, a lot of these other issues, such as loss of internal rotation, weak subscap, weak serratus, etc. are normally secondary issues. While it's great to work on these issues, if you don't find the root cause, pain may still persist. I find that typically the root cause of issues in the people I work with are depressed shoulders and a lack of upward rotation.
I'm not sure if you've read Shirley's Sahrmann's work yet but this is consistent with her approach. Downardly rotated scaps and depressed shoulders and are the most common things she finds with her patients. In her book she states that if there are associated issues, such as a winging scap, the primary diagnosis refers back to downwardly rotated scaps. It's not that you don't treat the winging scap, but the lack of upward rotation always takes precedent over the winging in that specific example. The rationale being the downwardly rotated scap occurred first, causing the winging scap later on at some point.
Correct the lack of upward rotation and you correct the downwardly rotated scap AND the winging scap at the same time. Correct the winging scap only though and you may still have issues.
Keep in mind this is with the people I deal with, which is much more of everyday people as opposed to your athletic demographic. However, I've found this holds true more often than not, regardless of the demographic. I have yet to see someone who needed to work on their downward rotators. Nearly every person I come across has forward head posture (indicative of overactive levator scap, which is a downard rotator), tight lats (a rarely talked about downward rotator), pec minor and rhomboids.
Just me rambling :).