See if can sort this out a little more among the ones I know about without confusing myself.
1st Platoon in order first to last
Gorecki...late 69 and maybe very early 70.
Premo.....first part of 70 and became XO from about June to the end.
At least one came after him. There was one guy who lasted only a few weeks before being reassigned. Think this platoon.
Moynahan, who has signed our book once, was leader end of 69 and into about the first three and a half months of 70.
Lawrence followed Moynahan and I think was the last 2nd Platoon leader.
Peck was the leader at the end of 69.
Hall followed him early 70.
The guy we don't know the name of came after Hall.
Of the others you name... Morgan was the XO for a while in early to mid 70. He was then assigned someplace else...or went home. Don't know. Macguire, sometime late 69 was re-assigned to another company and ended up wounded and after the war wrote a novel based on his recovering from wounds.