I really wish I could take the Coast Starlight -> San Joaquins without a bus transfer. Coast Starlight’s scheduled arrival in Sacramento is at 6:48am, the only departing San Joaquins train for the day leaves 20 minutes earlier. Meaning if you need to take SJ you have to wait, take a bus, wait some more, and catch up with another SJ train 3 hours later. I really wish they would run more trains from Sacramento but im sure this is coming in the future.
The northbound route doesn’t have a bus connection and just has you wait 3 hours in Martinez. Is this southbound transfer just because they assume they could have a delay so they don’t want to hold up the only southbound train from Sac?
My uninformed guess is that the timetable for those train services may be constrained by what the host railroads allow.