1500 torque peak and 4500 redline is drastically different than 3000 torque peak and 5000 redline.
Assume two cars, 1m circumference tires. Geared such that that in second gear, you hit torque peak at exactly 10m/s. (10m/s = 22mph. That's fairly fast for the bottom of second gear, but it keeps the math simple) At 10m/s, the wheels are spinning at 600rpm.
The 1500 rpm diesel will need a gear ratio of 2.5:1 to spin the wheels at 600rpm. At 4500rpm redline, the wheels will be spinning at 1800 rpm, which is 30m/s. (67mph) Which is pretty good for second gear.
The 3000 rpm torque peak American muscle car will need a gear ratio of 5:1 to spin the wheels at 600rpm. At 5000rpm redline, the wheels will be spinning at 1000rpm, which is only 16.7m/s. (37mph) Which is garbage.
1500-4500 rpm is an enormous torque band. 3000-5000 is tiny. Diesels are great like that; gasoline engines develop poor torque down below 3000rpms and need to be well engineered to rev into the 6000-10000 rpm range. The Europeans and Japanese have had it figured out for a while now; you'll see a lot of very well engineered v4's coming out of Japan and a lot of inline 6's, which are innately well balanced, coming out of Europe. American car companies have had an obsession with v8's, which are very difficult to balance, for years now - and they won't invest the engineering required to make them run smoothly. They sound great; you can't beat that deep throaty gurgling sound - the problem is that the deep throaty gurgling sound is a result of the poor engine balance which will limit the car to low rpms.
They have been making progress though. The z06/tr1 corvettes are amazing. Too bad the interior is shit, which is an entirely separate issue.
Remember: the engine with high horsepower in a wide power band will always win. "low end torque" is only meaningful if the gearbox has too few gears or if the driver doesn't know how to shift into the correct one.