You nailed it OP and volnpowell. It is a straight zone blocking scheme - no sprint draw features now except when they are in the pistol. Been explaining it for over a year. Fulton, James and Thomas are a step slow. Tiny is quick enough, just inexperienced. Stone is the quickest and very capable. They have even gone to the inside gaps trap block with the guards instead of the counter trey stuff they used to run because they lack quickness getting to the zones in time to create room for the RB. The other side to that is big guys with some athleticism can be great pass blockers - which is exactly what they have. With the great WRs we have - not a bad thing IMO.
Look at who they have recruited for the O-line previously and with the upcoming classes to see where they are going. I think you will see a significant difference and more of a modern version of our lines of the 90s.
They are making do with the current RBs. They do not yet have the all purpose backs they need (D-Green are you listening?). So they send in each one to run what they are capable of and try to run them in other formations/plays for experience when they get the opportunity like today. Example - DY running inside repeatedly today. Trying to get him used to it while finding a style and the plays that work for his size and skillset.
I could not be happier with what I see out of the coaching staff this season. This is just some of what Dooley and Saban call "the process."