Actually there are three peaks in that area named for John Marshall: There are North Marshall, South Marshall, and just to the east of them Mount Marshall.
I thought North and South Marshall were both part of the larger Mount Marshall. That is what it shows on the topo map. I don't see a Mount Marshall to the east. Can you elaborate? I have been up there a number of times, so I am pretty familiar if you can explain further.
The peak to the east, often called "The Peak" on maps is also referred to as "Mount Marshall." Perhaps a note to that effect would be in order.