I'm sure Robert will not oppose Matthew because of the entail.
And Carson always wants the best for Mary and he's sometimes like her father too when Robert isn't one. I just hate that towards the end of the season, we didn't see much of Carson & Mary anymore.
UGH. I hate S3 because of Matthew & Sybil's deaths. At the same time, that for me, was the show's last 'glory' season.