a good summary?

[Siren]

in 4D, nobody dies from these battles do they?

Physical death as a result of battle (or even "accident") is still very much possible. But perhaps we should note that these "battles" are both experienced and played out in an exponentially different fashion than the battles waged upon this planet's 3rd density. This is primarily because 4th density awareness represents a quantum leap in consciousness in contrast to 3rd density awareness.

They just get worn out and have to regroup as Ra calls it.

This "wearing out" and re-grouping occurs due to the fact that neither polarity of service accepts the form of service offered by the other; thus, they reject/repel each other and must re-group to continue their path in their respective modes of service. The battle should be seen as a friction (as previously stated), or dynamic tension. It offers a much more richer, vivid, vibrant experience of the Creator, by the Creator, for the Creator.

I imagine by the middle of 4D, battle might not be necessary when the social memory complex is formed. What do you think?

Various forms of "battle" will/do/have still occur(ed). This even extends into 5D.

Do not be distressed, brother. All is well.