It's true, NJT could run trains on your proposed schedule. Because of their aversion to speed and to expresses, they won't. They don't even run trains that run express from Morristown to Newark. Dover trains don't pass any stations W of Summit, except maybe Mt Tabor. They have enough traffic on that line to fleet trains like MN Harlem and NH lines do, with each train stopping at a few stations during rush hour, but they will not do it. I don't know where this snail's-pace mentality comes from. Shirley is long gone.
That's the point I was getting at, too. NJT has cut back on a lot of the express service in the past decade. The Tom Taber (Exp Hoboken to Chatham/Madison), the skip stops in the am (last stops Summit/Sh Hills), the Gladstone trains.
Looking at today;s schedules and comparing them to 1960, '60 is faster on apoint to point basis just about every time.
The old protocols had many trains run express east of Summit, with the locals beginning there. Then, some of these trains ran express east of SO, with locals coming out of South Orange