Despite the departures of Will Grigg, Febian Brandy and Jamie Paterson in little over a week, Smith told the Express & Star; "As far as I am concerned the two biggest signings we needed to make were always going to be Andy Butler and Adam Chambers.
"They are two fantastic professionals who the other lads look to for inspiration and leadership.
"Their professionalism is second to none and their presence in the dressing room meant they were always the most important ones for me to sign."