It is not the worsening driving skills. It is vehicle navmesh that is the problem. It tells where the bots could go when driving vehicles. They simply put a navmesh over obstacles, thick forests and so on. Thus you'll see bots in tanks at Bastogne trying to attack the town by going through the "thick" Ardennes forest without the same success as von Manstein did.
BTW, here is what I did (FH2.45 vanilla), 84 bots, skill 80:
Finished a round in Bastogne (once)
Bots fight fiercely, they also use smokes now to try to blind you. They also attack the objective relentlessly, making gameplay on both sides much more fun. Before this, the SP game of FH2 is usually fun in one side only, and the other is simply the receiving end.
I experienced a temporary lag (dropping into 2-3 FPS), but fortunately it resolves itself. And I didn't crashed as usual in previous FH2 versions (even with SP enhancements).
Crashed in Lebisey. (once)
I managed to play for about 30 minutes before crashing for unknown reason. The fight here is very fierce. The British come in swarms, almost mindless, but more coordinated this time. Their tank seems to prefer attacking the east AT position. It is very difficult to defend as Germans because the bots don't usually take cover, while the advancing British unleash everything they could while advancing. The MGs from tanks, Bren carriers, and even hip firing Bren gunners.
I was frustrated because of dying multiple times defending the first line flags. So I go to the chateau, find the StuG III G, drive them mad. But my armour was reduced little by little by distant firing Shermans, engineer bots trying to sneak through (but the satchel failed to attach), near miss PIAT rounds. All in all, the bots is more proactive in this one, despite numbering more than 64. No idle bots are spotted in German camps. Some are manning fixed emplacements like MGs and AT cannons, but generally they are aiming at something.
But then I crashed when the StuG III G is almost finished by a group of angry British engineers. It starts with a stutter in the FPS, a few seconds later it CTDed.
Finished a great round at Goodwood. (once)
Finally Goodwood is working! The bots now fight for Cagny. That's great to know that they are actively doing something, unlike in the previous version, where they wander the map aimlessly and happen to be near a flag and suddenly grow the urge to cap it.
I found that they can now drive tanks properly, navigating through the rail roads, passing the dig-in positions. I found one StuG hiding behind a building near the railroad crossing, apparently from a Sherman Firefly. It stay in hiding while my King Tiger exchanged shots with the Firefly. When I finally finish off the Firefly, the StuG come out and cross the road. I don't know whether this is just a coincidence or not, but it certainly is cool to watch.
Another cool bot behavior in this map is the tank platoon attack. The German bots somehow managed to assemble 2 Panthers, 1 Panzer IV, 1 Marder, and 1 StuG, but not including my King Tiger, to assault the Le Mesnil Frementel farmhouse. They seem to advance together, stopping when seeing a vehicle approaching the target, and exchanged shots briefly, then continues the advance. Almost realistic... a beautiful sight.
The Germans won by narrow 80-0 (from 5600 tickets for both, so that's a long fight alright), due to long fight in the Cagny streets. The excessive smoke, suppression effect, and many other visual enhancements in this release makes Cagny more lively than before. All in all, it is perfect!