They are one in the same. Resistance to landing supplies would come from shore batteries. You could not have said both the thing and it's opposite.
and the letter from the captain of the other ship shows that he was expecting 300 sailors to do just that,
No, he expected 300 sailors aboard Powhatan's gunboats to cover the expedition, not your "fighting sailors" whatever they are (note: sailors aboard a gunship would constitute 'fighting sailors' in my mind).
Then why was the captain needing 300 fighting sailors to land the supplies? The captain's letter proves that what I said was possible, contrary to your implications.
No, he expected 300 sailors aboard Powhatan's gunboats to cover the expedition, not your "fighting sailors" whatever they are (note: sailors aboard a gunship would constitute 'fighting sailors' in my mind).
That's not logical. If the captain was just needing the ship and not the 300 men, he would've just said that the ship was needed. He said he needed men, fighting sailors.
I think it's clear from this excerpt that he needed the three hundreed fighting sailors to get the provisions to the shore, not to man the guns on the Powhatan:
The heavy sea, and not having the sailors (three hundred) asked for, rendered any attempt from the Baltic absurd. I only felt anxious to get in a few days' provisions to last the fort until the Powhatan's arrival. The Pawnee and Lane were both short of men, and were only intended to afford a base of operations whilst the tugs and three hundred sailors fought their way in.
Come on now, you can't revise this, it's beyond credibility for you to try to change what this captain said.