Goal records mean very little in reality, look at Grigg and Stewarts records before joining and compare how they got on
We signed Stewart when he was like 24, Gallagher will be 29 a few weeks into the season. He hasn’t even managed double figures in the last 6 seasons, only hitting it once when he got 11 goals in his first season with Blackburn. If he’s not really scored goals for 7 consecutive seasons at this level through his best years I’d wager he’s not going to start now.