esopose: Ah, the "shit, forgot to turn in" moments :)
Those are quite tricky missions anyway. As a general tactic, although you're probably doing it already: stop the convoy from time to time and scout ahead to clean the path from enemies. Only move them when you're 100% sure the area is clear. Then rinse and repeat until you reach the objective area.
The AI in armored vehicles also has problems targeting infantry, particularly when they are prone or too close to the vehicle (something that you can exploit yourself in other missions). So it's better to either use manual fire or scan yourself for enemies (moving the targeting reticle around like crazy) instead of relying on the "Target" command. On the other hand, the AI will engage autonomously targets that you'd have never spotted (or not as fast), so it makes up for the mentioned shortcomings.
Thanks for the advice. I eventually got fed up with the mission and just accepted failure. Will probably go back and play it later, though. Escort missions = ugh, even in a game like this.
Now I'm on...is it 'Rolling Thunder,' maybe? One of the tank missions. Still much prefer being a footsoldier. Commanding a tank is a little overwhelming, and it's easy for my poor brain to get confused :3. But after all...the depth and variety of this game is what makes it so compelling. So I'll learn to like the tank missions.