The only bad thing is a semisubmersible floating mine would wreck havoc with them. Set the mine at 18-24 inches under the surface. Release one every 2-3 minutes ones bound to hit something. Then following mines would hit more frequently. Have the mines set for magnetic contact so a stump or anything like that won’t set them off. The mines in strings of 10-12 would hit something even if the ferries are moving.

Somore works awsome with trained crews works awsom I've seen videos using them in real time only you need to have a bunch of them for big crossing

in general, the only bridge for war is the MT72: it is made on the basis of a tank, it unfolds without human intervention at all, the crew is protected from the damaging factors present on the battlefield.
The rest is expensive and not much needed machinery. After all, outside the battlefield, you can simply throw pontoons with an ordinary crane. Or call civilian builders. Accordingly, there is no need to invent and build a "military" machine - which will be many times more expensive than the civilian equivalent.