All of this fiddling around with settings and bombarding for a couple of weeks only sets you up for a beating.
Your opponent will be getting Air Land & Sea elements into the area by every possible means.
Plus its going to take a long time to conquer the Pacific at those speeds.
IMVHO, if you are attacking a Bn sized force, take a Division plus support, 1-2 days air and sea bombardment and heavy units in the amphib TF. Upsize this formula as the defender number increase. Be 75%+ prepped and have competent commanders.
Dont fear overstacking, as long as you win the day it works, losing a few disrupted squads is acceptable.
As mentioned, bring extra supply while you reload the attackers and leave a garrison. Losing a few disrupted squads is acceptable.
Atoll invasions need to smash your opponent, not pry him out using minimal force and Clauswickinan tactics.
well, you can use a division on an atoll if u want to beat a
BN . I prefer one marine defense battalion, one combat engineer, one naval support section, and one tank unit. I find this gets the job done.