only 1/4 of the casting was new/changed
Core fireteam yes but overall it was closer to half.
RDJ actually left after s8 preceded by Don S David leaving at the end of s7 to make things easier for RDJ acting wise who wanted to stop and spend more time with his daughter. Changing Jack from in the field to behind a desk made things easier on RDJ but even then that only lasted a single season before Beau Bridges came in as Landry.
So in addition to the "team lead" being replaced with Mitchell so was the base CO.
As was the lead medic, finally, when Lexa Doig was cast, a casting that would lead to her marrying Michael Shanks.
That's 3 of the main 6 swapped out in some way or another, although Fraser was certainly more of a secondary supporting character than Hammond ended up being since originally Hammond was far more antagonistic.
Ben Browder did a pretty good job, but I don't think he was "quite" the right fit as the stand-in for the new team leader
He was originally going to be cast as Sheppard in SGA but the filming of Farscape: The Peacekeeper Wars prevented that. Instead Cameron Mitchel was created filling a similar role but on the parent show rather than spin-off.
Claudia was, so hit or miss. 60% miss I'd say, and I think a lot of it's because the writers just couldn't narrow down who her character should be for the longest time
Vala was never intended to be a recurring character, or even return after her initial appearance in 'Promethus Unbound' in season 8, so the character the show ended up with later on was very different to the previous one off she was expected to be. It wasn't helped that Claudia Black's pregnancy also interfered with her appearances after 'Beachhead' in a similar way to Amanda Tapping's prior to the same episode. In Sam's case however they "phoned her in" during her chat with Mitchel in the s9 pilot so any evidence of her own pregnancy was minimal across a screen and required zero mobility and it was resolved by episode 6 rather in Vala's case where it started, meaning she would miss most of the rest of the season.
only 1/4 of the casting was new/changed
Core fireteam yes but overall it was closer to half.
RDJ actually left after s8 preceded by Don S David leaving at the end of s7 to make things easier for RDJ acting wise who wanted to stop and spend more time with his daughter. Changing Jack from in the field to behind a desk made things easier on RDJ but even then that only lasted a single season before Beau Bridges came in as Landry.
So in addition to the "team lead" being replaced with Mitchell so was the base CO.
As was the lead medic, finally, when Lexa Doig was cast, a casting that would lead to her marrying Michael Shanks.
That's 3 of the main 6 swapped out in some way or another, although Fraser was certainly more of a secondary supporting character than Hammond ended up being since originally Hammond was far more antagonistic.