I think Simmonds was chosen over Perry. Let's not forget, the Habs had Perry in camp, then cut him, eventually bringing him back as an injury replacement. There are pros of Perry vs. Simmonds but also pros for Simmonds. I don't think Dubas envisioned he would need Simmonds or Perry for their scoring prowess, as both have seen better days. I think this could have come down to Cup experience vs. physicality, fighting, and the ability to police a game if needed. Simmonds is, and always was, a way better fighter than Perry. Simmonds can actually hold his own with any player in the NHL today, perhaps sans Reaves.
Should Dubas have signed Perry instead of Simmonds? An argument could be made but we'd have to look at timing. As I said, Perry was Habs property twice since camp.
I think Thornton was brought in for three reasons:
1. Motivation. The only thing missing from Jumbo's case is a Cup. Want to talk about motivation?
2. Role model. Granted, Thornton never won a Cup, but either did Ray Bourque until he arrived in Denver. Jumbo is a legend and a player the kids looked up to over the years -- having him in the room to help mentor them should have been extremely valuable. What I don't agree with is Keefe giving Thornton tons of top line and PP time during the first half of the season. I always thought that was happening because the kids told Keefe they "wanted Joe on their line" -- it just had that feel to it.
3. Versatility. Joe could play wing or middle. Perry is pest winger with decent, aging mitts. He is not versatile, nor can he be used in multiple roles.
Looking back, a player like Jeff Carter would have been outstanding, but he came with a big sticker that the Leafs couldn't afford.