Strength as a skill is such a crucial concept when considering the transfer of strength. Squatting carry-over to sprinting is a great example. In my experience with myself and others, an exaggerated focus training heavy squats will not get you fast (usually in my experience it's just the opposite). I've heard a number of theories about this, like it suppresses the crossed extensor reflex, or the focus on bracing begins to interfere with relaxing during the explosive work, etc. And there are just too many sub 10.5, even sub 10, sprinters who can barely handle bodyweight, much less double bodyweight squats. This isn't to say that heavy squatting can't help speed, but that it has to be incorporated in a way where the body can make use of the strength while you develop it. Maybe a good question to ask when designing your program is whether you need to improve neurologic v/s muscle density/hypertrophy v/s connective tissue strength, etc, and then program accordingly. Of course this example doesn't directly address the question of strength v/s strength endurance in the original post, but I think similar questions probably apply.