I think we have a shared interest in 1815. I would highly recommend you find a copy of "La Campagne de 1815, Mobilisation et Concentration", Commandant Jean Regnault, 1935. I just checked Bookfinder and there is a copy available at a very good price. I don't know of any electronic copy as of yet.

I am not sure of Plotho's sources regarding the National Guard, but he was writing immediately after the war, which has pluses and minuses for research. You may note that the size of the NG divisions in Plotho seems to be out of alignment with any other source and would suggest that his information in this specific is not correct.

Regnault, Annex I D, pp 272-275 provides the following for the 2nd National Guard Division as of 15 June 1815:

General Rouyer
Effectif prevu: 10 batallions reunis a Nancy
1ere Bde: General Lefebvre - 9e, 10e, 11e, 12e, 13e, 14e batallions des Vosges
2e Bde: General Lebondidier - 11e, 12e, 13e, 14e batallions de la Meurthe
Effectif le 15 juin: 10 batallions - 5.622 hommes
La 2e Division remplace le 4e corps en avant de Thionville, le 9 juin a Havange et Richmemont.

Annex 1 B, pp 257-258 provides the strength of each individual battalion on 15 June 1815:
Vosges 9e 615
10e 486
11e 618
12e 511
13e 566
14e 641
Meurthe 11e 520
12e 547
13e 496
14e 622

pp229-230 discusses the state of the 3rd and 4th Military Divisions (Vosges and Meurthe were in the 4th MD) and confirms that Rouyer was covering the Moselle frontier after IV was shifted west. So the actual 2nd National Guard Division was NOT present at Charlemont.

However, pp230-231 describes how Napoleon ordered the use of a portion of the National Guard in garrison in the 2nd Military Division, which was headquartered at Mezieres. On 13 June, he ordered General Dumonceau to assemble one third of the garrisons of Mezieres and Givet to manouver towards Dinant. On the 14th, Dumonceau left Mezieres with the 5e et 6e batallions des Ardennes for Givet. There he added a part of that garrison and on the 17th exited Givet with about 3,000 men and crossed the frontier (which was still manned by Netherlands customs agents). On the 18th Grouchy ordered Dumonceau to occupy Namur, but Regnault doubts this actually happened since there is no trace of these units in Grouchy's army after June 20th.

I am not sure how these 3,000 men were actually constituted, since Annex I B shows a total of 4 battalions at Givet.

Now if you want to confuse the picture more, the 5e and 6e des Ardennes may well have been in a condition to march since those battalions were allocated to the 1st National Guard Division, which was ordered to assemble at Sainte Menehould (mid way between Reims and Verdun). This 1st National Guard Division was to be formed from battalions drawn from the 2nd Military Division. However, only one battalion had actually gone to that location. So the 1st National Guard Division really only existed on paper at this date, and it looks like most of its allocated units were in the end scraped into the ad hoc force directed towards Dinant and then Namur (see Annex I D, p 274). It is quite likely that this reflects the haste with which the army was assembled. It could also be a deliberate deceptive measure, with the intent being to make it appear that a NG division was in place at Ste Menehould, when in fact it was really en route to occupy Namur and cover that flank of the main army.

pp231-232 describes similar operations on the left flank of l'Armee du Nord, so you can see why I view this book to be a "must have".

In summary, the orders pertain to National Guards in the 2nd Military Division, not to the 2nd Division of National Guards itself. Other than the commander and the 5e and 6e des Ardennes, the composition of this force is not known to me, though I suspect it includes some of the battalions assigned to the 1st National Guard Division. I hope this is of some help. Regards,

David