Question from original to definitive

so its been a long time since i played the original but i remember their being a campaign mission where you had to fight two enemies. one of which started of on a landmass next to you, the other was on a landmass connected to your own via a small slither of land that was completely blocked by trees (for what ever reason the boat techs were missing i believe, maybe a demo or scenario relevant?) does anyone know which campaign this belonged to and which one i would have to play to do it again on the definitive, also has anyone else noticed the mission lists to be different and in a different order?