WW2 myth busting info sought

[Ed Landstrom]

Another illusion shattered. As far back as I can remember, the conventional wisdom has been that:
The Sherman's vulnerability was due in part to its high profile.
The high profile was necessitated by the radial engine initially used.
The radial engine was used because it was the only engine powerful enough that was available in quantity at the time the Sherman was being designed.
When other engines became available, the Sherman design wasn't modified to reduce its height because that would have delayed production.

Now that the first premise has been debunked (Is it possible that nobody bothered to look up the actual dimensions until now?) does anyone know if the others are also myths?