For me the problem with this rule is that we must assume skirmishers are already built into the game mechanics at the level that is suggested. Light companies were routinely used in a skirmishing role ahead of the battalions, so we would have to assume that units not deploying skirmishers were failing to function 'normally'.
It might be worth noting that larger groups of skirmishers as often deployed by the French are also sometimes represented in the game. In the Vimeiro battle, the presence of French light infantry on the left flank seems to be intended to represent light companies detached from their parent battalions (much like the combined grenadiers) as there were no light infantry battalions in that part of the battlefield (unless there is information that I haven't come across. Incidentally, by the same token, French light infantry on the right of the battlefield appear to be represented by line infantry units, suggesting that the distinction may sometimes be used to represent formation rather than regimental designation.
If everyone made war only according to his own convictions, there would be no war.