I have to admit having only read a dozen or so 40K books my knowledge of "new" background on the marines isn't the greatest.
Could someone list me a few books which show the marines fighting en masse as a ground force where there are no Air assets or Titan allies so I can catch up with the "new" background

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The only books I've read where marines have had no support has been small scale actions,forces as small as Epic A formations not Epic A Armies.
Onto the List.
I don't think the Codex Marine list should be forced into an all round list,it should be re-named as an Air Assault/Invasion force list with new variant lists done to make other styles viable.
I believe there are to many variables to make an "All round/All in One" Codex list where every style of Army is balanced and points costed correctly.
As I see it changing the points for Air assets etc. to make an all ground force viable in this list is then going to make the Air Heavy list overpriced.
We are then going to be in the same boat where instead of ground forces being overcosted just incase they are Air dropped to be where Air Transports are going to be overcosted to use as viable Bombers.
It may make "ground pounders" a more viable force but what about the players who use the Air Transports just as Bombers, they are then going to be paying over the odds.
Why should "Player A, I want to use an all ground force" wishes come above "Player B, I want to use my Air transports as purely Bombers without using them for Air Assaults".