As for the rest I have found that it is the little overlooked nuts and bolts details which would often times explain why the generals did the things that they did and make the decisions that they would. How a regiment or brigade was armed in some cases would determine how it was used on the tactical battlefield.
Every gun, especially in the napoleanic era of combat, was not just a gun. They had difference capabilites which could be used to specific advantage to the smart commander. For example a regiment armed with repeating carbines would have a decided advantages over one armed with single shot smoothbore muskets. However at close range within the Smoothbore musket effective range the smoothbore musket were extremely deadly.
These different capabilities were often combined in a single regiment.
As with the 26th Ark. being sent to DeVal's Bluff at a time when there was a threat to that place would indicate the 26th Ark. was probably one of the better armed regiments, even with the request for 300 pikes, of the period even as poorly armed as they may have been. That would attest to the overall dire circumstanes of that period.