I have a question regarding amphibious assaults that came up in my last game:

I was playing Germany and I was going to conduct an amphibious assault against London. I had 3 transports off the coast of Norway that loaded 2 infantry and moved into the channel with a battleship, a cruiser, and an aircraft carrier supporting. In the channel was 1 destroyer. Since in the rules it states when conducting an amphibious assault you must make the sea zone you conduct it from friendly through a naval combat, and that when conducting an amphibious assault you may load troops from any territory along your transport’s movement path, am I able to load 3 tanks and 1 additional infantry from Normandy onto my transports and have them participate in the amphibious assault after my ships have destroyed the destroyer?