I think we would be stupid not to go for a goalie who knows the league and the club inside out, has won the league twice, play offs twice and challenge Cup twice, with him playing in almost every game. Tier 1 Intentional starting goalie, decent stats in Europe. And crucially will allow us an extra import skater.
You could argue very successfully that Carruth is the 'better' netminder on the ice, more entertaining too, but when looking at the whole package, including his personality/mindset, for a team environment is it actually better? After all, Mac has won bugger all in his pro career.
He might not be available anyway, or might not want to come back. But to turn our nose up on our most successful goalie of all time would be silly.