It seems that the past popular opinion is that, we assume, Steele was making a flanking movement to the south of Little Rock and not a change of base. It would seem that the Confederates still held the advantage of the interior lines and defensive position maybe not a prepared position as strong as the Bayou Meto works, but which could have held Steele back. That once Steele crossed the Arkansas he had effectively cut himself off from and abandoned his supply lines at Brownsville. Steele could not have foreseen the rapid and total collapes of the Confederates at Little Rock.
It would seem that had the Confederates resistance not so suddenly collaped and made a strike towards Brownsville, Steele would have been in serious trouble. Had Price captured Brownsville even if Steele had taken Little Rock, Steele would have had to reopen his supply line one way or the other. Either back through Brownsville or through Pine Bluff and the Arkansas River, which was not a reliable route at that time of year because of water levels. Steele could not have stayed in Little Rock or advanced without his supplies.
While I know that would have been a bold move on the part of Price, I would think that this was a dangerous move on the part of Steele had anything gone wrong.