It's all about the front end. Yes, there is more frontal area. On an airplane, the fuselage has an element of lift by acting sort of as an airflow. This cancels out a little bit of drag. Otherwise, nothing can't overcome drag with plenty of power.
These do the same.
Worth noting that the E1 and E4 both have max speeds of 240 kph, regardless of 12, 10 or 6 cars.
Back to the TGV, I'm fascinated that these have top speeds of 270 and 320 kph. Having power cars vs every car powered lengthens the train, offsetting capacity. But apparently the big difference here is the 6.72 MW vs 9.28 MW power output. In these two cases, though, the E4 Shinkansen carries 817 passengers vs 508 on the TGV.
It's all trades. Power, speed, passenger count, train configuration. Whatever meets the business case.
FWIW, the top speed Sanyo Shinkansen (the extension of the Tokaido) is the N700 at 300 kph. For a single level, 16-car-powered train, it's power output is 17.08 MW! But it also carries 1,323 people. So, 2.6x the capacity of the TGV, with only 1.84x the power.