I agree with your summation. I'll take it further. Malcolm Brown has been a very physical runner who hits the holes hard and grinds for extra yards. He seems to get injured every season, eventually. Henderson missed nearly all of last season and is injured again. Two injuries and Akers is left on an island. What are they going to do? Sign CJ Anderson off the street? Akers is an unproven rookie and it would be best if he had some experienced backs, or at least healthy backs in the room. And if Akers can't pass block, combined with this Oline Wohlford may suddenly find himself starting, if you know what I mean.
Fournette could really help this team out. He's the closest I've seen to an SJ type of runner. If the Oline hasn't improved in run blocking, which we have no indication it has, we could use another power runner in the mix. His pass catching fits the offense too.
So how do the Rams get it done? They'd obviously have to create some cap space. I don't know if they restructure some players or trade/cut. But if they got Fournette cheaply enough, say a third of second rounder and a player or two, (some mentioned Havenstein, Maybe David Long or Troy Hil) then don't resign Fournette after his contract ends and get the third round comp pick. It could be well worth the gamble.
The only hurdle I see is would Snead have a hard enough heart to send any Rams players to Jacksonville? So it would likely be a Fournette for draft picks. Which I prefer not to trade a first for a one year rental.