It's 8-10 hours to transit the canal. Assuming a train is faster, you'd still need almost 40 trains to carry the same number of containers...are 40 trains still faster in total?
Sure, you could scale it and build 10 train tracks side-by-side (whoa!) which would support 5 trains in each direction, and then you'd only need to get 8 trains faster in total.
And that's disregarding the 3-4 days needed on either end to unload/load the ships.