This generation Sambar came with a 1,200 cc engine (in addition to the 544 cc kei engine) and I suspect that’s the one we got in Denmark. That puts it outside the kei car category, but you still need five of them to have enough displacement to surpass that of the Econoline (if it’s the 351 Windsor in the Ford).
What’s more interesting, though, is that you could almost drive the Sambar into the Econoline through its back doors. The rear door opening is 54.4 by 46.8 inches. The Sambar’s dimensions are 54.9 by 69.3, so it’s a bit taller, but if you could open the doors of the Econolline all the way up to the raised roof on this example and fold in the mirrors on the Sambar and deflate the tires a bit, it just may actually fit. If not, you can at least have some fun saying that you tried to put a van in a van in vain.