Why is the 767-400 cockpit different?

When Boeing built the 767-400, why was the cockpit layed out a 747/777 style? it has the all glass cockpit, has a MCP like the other 767s & 747s,
but obviously as its a twin engined aircraft only has two thrust levers so its like a cross of a 747 and 777 in ways.

but why didnt Boeing make it the same layout as the other 767 series? to me it doesnt make sense, i read on the airliner.net website crews can still fly all 767 series (also like how some crews fly say a 737-300 one day and -700 the next) but wouldnt the pilots need two sim assesments as its almost like a different aircraft instead of just 1 every six months?

Whether the flight instruments are the old “steam gauges” or the new flight display as shown on a cathode ray tube just does not make much difference to the pilot. It is all of the other facets of dealing with the airplane, such as using the checklists, and dealing with emergencies, that make a type of airplane “unique.” The 767-400 may have different cockpit displays, but is still a 767 as far as the flight crew and the FAA are concerned. American Airlines is in the process of switching all of the 767s and 757s to new style flat panel cockpit displays. They say it will save on maintenance costs, and reduce the operating weight of the airplane by about 100 pounds.

Also the 767-400 is the last of the current production Boeings that has not been converted to the LCD cockpit display technology. Which as mentioned is lighter and much more reliable than the old CRT technology. There’s also a cost savings to Boeing and operators in that the equipment is common from fleet type to fleet type.