Sir Sean Connery was a selective actor

I don’t think he’ he’d be a good Gandalf anyways

nothing against him, but what we got was perfect. 

He would’ve been awful. Connery was good at playing smarmy dickheads, but he was kind of ass any time he wasn’t playing a smarmy dickhead.
This is why is performance in The Rock is pitch perfect.
Exactly. He may not have been a great actor in terms of range or depth of character, but no one else is delivering a line like “Losers whine about doing their best. Winners go home and fuck the prom queen” like that.