Fred Diegtel was Vice President of Operations on the Erie Lackawanna when I worked in Hoboken 1968-70, and he had held that position for quite a while before that.
I was the Assistant Division Engineer, and the only person in my "chain of command" who was not ex-DL&W was Gregory Maxwell, President, ex-New York Central.
Even though the Erie people seem to have had the upper hand early in the merger, the DL&W Engineering Department officials were younger. They outlasted the old Erie heads, and eventually they prevailed.
I agree with WDB about Shoemaker. His group eventually did a fine job against overwhelming odds. But the operating philosophies and personalities of Erie and DL&W people were separated (to be polite) by the earliest management of EL, and to a large degree that separation was never overcome. It was a dark cloud over the Erie Lackawanna until the end.