Sinnott told BBC Radio Stoke: "It is painful but we could look back in three or four years' time and think we did what we did because it was necessary.
"We needed to act to try and achieve something like what Doncaster and Carlisle have. That has to be the aim."
Sinnott has released 13 players and signed 6. He hopes to bring in a couple more as well.
"Sometimes players can come together and it doesn't quite click, I think we suffered a little from that last year," he continued.
"You could go into the basics of saying we conceded too many, we didn't score enough goals, we were unlucky. But at the end of the day last season things didn't happen and they didn't happen for a reason."
And now he's hoping his transformation will address the problems and set Vale on the up next season.