Hi Ian!
As for the graves, one thing seems to be clear: they are located outside the fort. The presence of the Heer soldier together with the Fallschirmjäger is a sign that they might belong both to Kanne and Vroenhoven. Furthermore, it´s very likely that the elevation on the right side of the photo is the border of the dith of the "Albert Kanal". As you point out, some Fallschirmjäger were buried close to the bridge in Vroenhoven (as far as I know, there were several close to the west bank, right to the south of the bridge...). It´s also known - as you say - that 7 of the 8 fallen in Veldwezelt were buried in a row, together with a Belgian soldier, at the west side of the channel near the "Nicolaes restaurant", blown by "Trupp Ellersiek". As we could discuss weeks ago, the other Fallschirmjäger casualty might well be Von der Ruhr (although killed in Hees...). The German war grave service made some faults in this regard; the case of Kanne is illustrative of it: it seems that every dead body found into the borders of the community of Kanne was reported as belonging to Vroenhoven. There was no community of Kanne for the official records! But this issue is another tale...
Let´s get to the point: The Belgian pression against the Fallschirmjäger holding Vroenhoven was very high. At 12:50, the first Heer units reinforced the bridge. At 18:30 the Belgian tried to destroy the bridge with artillery fire. Heer and Fallschirmjäger soldiers fighting hand to hand...
Regards. Óscar