I think the call for the large CSA army was in direct response to Lincoln's first inaugural speech of a few days earlier. It was widely interpreted in the South and in Democratic circles in the North that Lincoln's speech was a in effect declaration of war. See A Declaration of War?.
Here is a newspaper item dated March 5, 1861:
Latest from Montgomery
War considered Inevitable -- The Standing Army -- The War Strength
Montgomery, March 5 -- Since the receipt of the Inaugural address of Mr. Lincoln, it is universally conceded here that war between the Confederate States and the United States is inevitable. Mr. Benjamin said last night, that in his opinion, there would be a clash of Arms within thirty days.
Mr. Conrad concurred in this view of the aspect of affairs. The standing army of the Confederate States will be fixed at ten thousand men. Congress is now engaged in organizing the army. Of course, in case of hostilities, the number of men put in the field will be greater. It is calculated that the States now composing the Confederacy can place 80,000 on a movable war footing. [Source: Gazette and Sentinel, Plaquemine, Louisiana, March 9, 1861]
In such a situation, Davis would have been remiss if he did not prepare for what might happen. Here's the first part of the March 6 act that authorized Davis to call for volunteers if and when needed:
The Congress of the Confederate States of America do enact, That in order to provide speedily forces to repel invasion, maintain the rightful possession of the Confederate States of America in every portion of territory belonging to each State, and to secure the public tranquility and independence against threatened assault, the President be, and he is hereby authorized to employ the militia, military and naval forces of the Confederate States of America, and to ask for and accept the services of any number of volunteers, not exceeding one hundred thousand, who may offer their services, either as cavalry, mounted riflemen, artillery or infantry, in such proportion of these several arms as he may deem expedient, to serve for twelve months after they shall be mustered into service, unless sooner discharged.
I note that these volunteers were intended to protect against invasion, maintain possessions (no doubt including forts) within the Confederacy, and secure independence against threatened assault.
what did he [Davis] come up with? Nothing, except force. Almost as if he wanted the war to solidify his government's position.
Nothing except force is incorrect, but he may indeed have wanted to solidify his government's position by firing on the fort to precipitate the secession of border states. Lincoln probably had ulterior motives as well. Lincoln wanted to get the North solidly behind him, and provoking the South into a fight was certainly one way to do it. As I've said on these threads before, IMO Davis blundered by firing on Fort Sumter. It would have been better for the Confederacy if he had waited for a situation where Lincoln was more clearly in the wrong. (That's easy for me to say almost 150 years after the fact.)
Given that pro-secessionist forces were already seizing US forts, stealing federal property and threatening unionists, one can be skeptical of such professions. It's the kind of boilerplate that politicians use to conceal what's really going on.