I didn't claim using low inlines you train more outer than inner part of the chest, no
i claim that at these angle you train the most fibers that go from the inside to the outside, instead of top or bottom of the chest, hence this way you have a fuller inner AND outer chest wearing a tanktop
Some people even argue that we even shouldn't do incline benchpressing as "it is not possible to hit upper chest" or that we "shouldn't do flatbenchpresses" because weighted dips would take care of the whole chest.... etc... I agree that way too many people dream up fancy angles exercise and equipment and drift away from the basics, but other people turn to nihilism...
About the vastus medialis and the vastus lateralis
Try HACKSQUATS in 2 variants:
1. feet at shoulderwidth in front of you (like smith machine squats) toes slightly pointing out , more medial action
2. close stance, feet directly under your torso, feet forward (it will be nearly impossible not to lift your heels when going down),
more lateral action.
I did variant 2 for 8 weeks and made improvements in my vastus latereralis as opposed to normal hacksquats. While it's true you cannot change genetic muscle shape, it is the determined training that will reveal if you were born with peaked biceps or not, also you can EMPHASIZE parts of muscle as (depending on you biomechanical build) certain exercise skip certain fibers of a muscle. In most cases there is considerable overlap , in the sence that it's very hard to solely focus on the ie. triceps lateral head, but certain exercises get this head better into play than others
Why do you think free weights are considered superior to machines???
Oviously the machines stimulates a smaller area, so there is your clue that to a certain degree the choice of exercises does play a roll in sculpting, however you have to do this in a hardcore way and for a considerable time to make a significant differance (best example Larry Scotts peaked biceps) Maybe he had them all along, but it wasn't until Larry Scott curls that they showed off.