The AH default bridges wont allow gvs to cross water tiles.
If you remember Niemen the bridges were made from runways and pillars. Some of the bridges would allow GVS to fall through unless you went across a high speed.
Kantorri came up with a "flat bridge" that is functional and destroyable.
There are only 2 "large" rivers because water tiles are 1 mile wide. This area actually had many small rivers and streams that we could not add because with 1-mile wide water tiles they would eat up a large part of the land area.
With just 2 large rivers, 1 being outside the battle area, there was no real need for the fords. The 1 river that is in the battle area runs N / S and there are attack lanes on either side of the river. Even if the bridges are destroyed it won’t stop the battle. In Niemen when a VH or bridge was destroyed that pretty much ended the frame for some of the groups. The idea behind including fords was keep the battle going. I thought if a bridge is destroyed then the players would then need to locate a shallow water crossing (Ford) to continue. As it turned out I don’t think we need them so they were left out.
The "defensive V-bases" were designed with the idea that it should take a combined arms attack to break through fixed defensive positions. There are 12-manned ack (AT guns) inserted along the walls and there are 3 shore batteries that can be used as artillery. You can actually shell the enemy defensive v-bases with the SBs.
In fact we will give the Soviets 5 min before launch to shell the German defenses. In the real life battles the Soviets opened up along the battle area with hour-long artillery attacks, the followed up with "break through" tank brigades and shock troops.
The German were able to repel the Soviet assaults by creating a series of fixed defensive positions. This area was full of forests and marshes that pre-defined the attack lanes. This is where we placed the defensive v-bases.