The Grande Armee in 1805?

I was quite confused by the sources I've read about Napoleon's Grande Armee in 1805, the seven corps were each commanded by a marshal respectively, but some sources said the II Corps was commanded by Marmont (who was only a General de Division by that time), but some said it was commanded by Massena in Italy. But I thought that Massena's Italian Army who fought Caldiero wasn't a part of the Grande Armee's seven corps. It's quite confusing because Marmont was not a marshal and wikipedia said Brune was commanding in the English Channel and St. Cyr in Liguria.
So:
I Corps-Marshal Jean-Baptiste Bernadotte
II Corps- GD Auguste Marmont or Marshal Jean-Andre Massena?
III Corps- Marshal Louis Nicolas Davout
IV Corps- Marshal Jean-de-dieu Soult
V Corps-Marshal Jean Lannes
VI Corps-Marshal Michel Ney
VII Corps-Marshal Pierre Augereau
VIII Corps (later raised)-Marshal Edouard Mortier

http://lesapn.forumactif.fr/les-mare...pire-t2238.htm

Well this site says of Marmont 'He was not included in the list of Marshals in May 1804 . That did not prevent him fighting bravely at Ulm and Weyer (in 1805) at the head of the 2nd Corps of the Grande Armee.'
I suppose that means he was commanding.

See http://www.cgsc.edu/CARL/nafziger/805HAH.pdf for Orbat of Grande Armee.

Marmont was promoted to the Marshalate at or soon after after Wagram in 1809 along with MacDonald & Oudinot. Suchet received his baton in 1811; St Cyr, Poniatowski & Grouchy got theirs in 1812, 1813 & 1815 respectively. Victor received his in 1807.

Perhaps the Corps were theater specific?

Massena's Army of Italy did not initially form part of La Grande Armee - this was reserved for the forces under Napoleon's command. Massena's Army was not organised along Corps lines see Orbat: http://www.cgsc.edu/CARL/nafziger/805JBG.pdf
St Cyr from what I recollect was in Etruria (not Liguria) guarding Massena's backside from a possible anglo-russian descent; you will see he is shown as commanding the right wing of the Army of Italy - see http://www.cgsc.edu/CARL/nafziger/805KCF.pdf He ended up commanding the Army of Naples http://www.cgsc.edu/CARL/nafziger/805LCR.pdf
Brune's Corps was left on the coast of the English Channel to deter any invasion by the British.