Hm, indeed. If you look at the recons (can move every 20 ticks) and the lt crossing their ways you see the lt making his 2nd movement onto a hex before the rec could go onto it. The recon didnt move the round before so should be able to move on tick 1 and 21. But that would mean the lt moved on tick 1 and 21 as well. So he could move on tick one in the round with the aa crossing his way as well.
So i think marking his way one more hex (as you can see with the v key) could make him move earlier (i know that a unit with 4.5 movement can move 4 in first round and 5 in the following, if you mark his way for 5 hexes in the first turn already, but not if you only mark 4 movement).
All in all: Movement is pretty complicated and will never be understood for 100%