Johnston was one cog in the massive manhunt, and his running across the trail of Bill Anderson was happenstance. What the Confederates did with that happenstance was certainly brilliant tactically.
To illustrate the extent of the manhunt that was going on, it should be noted that two Federal generals, Clinton B. Fisk and Joseph B. Douglass, were leading it personally, and had been in the saddle for weeks. This was a very unusual use of general officers---personally leading units as small as company sized in the pursuit of guerrillas.
Major Johnston had a battalion of the 39th Missouri Infantry at Paris, Mo., while the c.o., Colonel Edwin Kutzner of the 39th Missouri, was at Macon with the rest of the regiment.
Confederates Tom Todd and George Todd overran the Third MSM Cavalry at Goslin's Lane on Sept. 23, 1864. Bill Anderson and his force combined with the Todds that night, with the Fayette fight occuring Sept. 24. On Sept. 25, they moved on to Huntsville, and unsuccessfully tried to get the Federal force there to surrender to it.
Of course this had the Federals, who had been chasing their own tails for weeks, hot on the tails of the Confederates.
On Sept. 26 the Federals received word that the Confederates had crossed the railroad line near Allen (now Moberly). At 1:30 that afternoon it was reported that Major Austin King, with 200 troopers of his 6th MSM Cavalry, was "very near" to the Confederate rear guard, and had "captured and summarily mustered out" a few of their stragglers.
With the end game seeming to be very near, General Fisk sent word to all available troops to tighten the noose, with elements of the 9th MSM Cavalry ordered to join King at Renick, while the 1st Iowa Cavalry under Douglass was detailed to the Perche Hills north of Rocheport to block avenues of escape (note that Sterling Price's Raid was unfolding, and that thousands of Federal forces were just beginning to form to the south and east of Fisk to meet that threat).
Fisk telegraphed Col. Kutzner at Macon, instructing him to send a rider to Paris with orders to have Major Johnston join the 6th MSM Cavalry and 9th MSM Cavalry at Renick. This rider reached Paris on the night of Sept. 26. Johnston dispatched a message back to Kutzner, advising him that he had obtained mounts for his men, and had broken up the rebel bands in his area of operations to the point that they had become "skulking squads." He closed with "I have no time to write further," sent his message off, called his men to horse, and headed out into the night at 10 p.m.
He initially had 145 mounted men from Companies A, G, and H, along with 25 footmen from Company H. Heading toward Renick, as per orders, ten miles out of Paris he ran across the trail of the Confederates. At that point he made a judgement call, deviating from his orders and took up the pursuit. At the Long Branch of the Salt River near the Audrain County line, Johnston had 1st Lt. Frank Ray proceed back to Paris with the 25 footmen and then went into camp with his remaining force.
Soon Johnston's scouts came in with reports that a body of irregulars were a couple of miles distant. Johnston viewed these men through his field glasses, and dispatched a scouting party to follow them while he rested his main body. Later, he resumed the pursuit, taking up a southeasterly line of march. Ultimately he ended up three miles east of Centralia, where he spotted the smoke coming from Centralia and detoured toward it.
While Johnston was in town, word reached George Todd to the south-southeast. Todd ordered John Thrailkill to approach Centralia with ten men and to determine the numbers and intentions of the Federal force. Thrailkill sent a runner back to Todd with the information, after which Todd relayed instructions back to Thrailkill to decoy the Federals back to his possition.
Thrailkill came out into the open, after which Johnston, who had gone up to the garret of the town hotel, spotted him and his handful of men. Johnston sent a rider to Sturgeon with orders to summon reinforcements, and then left a skeleton crew in town and headed out after Thrailkill. Thrailkill toyed with Johnston's advance for a mile, falling back, before he "suddenly wheeled and charged them, sending them scampering...."
Anyway, Johnston pressed the pursuit, with Thrailkill decoying him every step of the way, right back to Todd and Anderson, who, by the time Johnston arrived, were more than ready for him. The Confederate plan, which appears to have been put together on the spur of the moment if the sources are to be trusted, was no less than brilliant.
Much is made of the disparity of firepower, and Johnston taking his mounted infantry with single shot rifles up against well-armed guerrillas. One thing I have never seen is anyone actually do the math. Once you do, it is breath taking.
Think about it--around 110 Federals, totaling....110 bullets, give or take a few. Against around 400 Confederates. Four to six pistols apiece. Each pistol with six shots. That is 12,000 shots, give or take a few shots....