Convoy strength display

It's cool that the unit info is showing strength stats for sea convoy's. However, when a plane is in a land convoy it doesn't show any strength stats. Does this mean they are zero as indicated by the FIST number or are they just not displayed correctly for land convoys? It does seem a bit suspicious though because when you march a plane into the water it has sea convoy strength stats.

On a related point, the displayed strength stats for (dis)embarking units seems a bit strange. If you start embarking from land there is no change in the displayed unit stats from what it was before it started embarking. If you then start disembarking (back to land) it still shows the original stats. However, if you start disembarking from sea, it shows the sea convoy stats. If you reverse it and start embarking it remains as sea convoy stats. Basically, once you start embarking/disembarking the stats remain the same as they were when you started. Surely this isn't correct.