ORIGINAL: herwin
Please describe the operations that should be used to capture Manila and Singapore. Unfortunately, I lack experience with the game system and so tend to use the task organisations I would have used in reality. Spending seven years as the chief systems engineer of a command and control system for corps-level amphibious operations can have that effect.
By the way, I just acquired a copy of Military Modelling for Decision Making, 3rd edition, Wayne P. Hughes, Jr., ed., 1997. Starting on page 50, there is an essay by Hughes "On Model Stricture, or Stifling Thought", where he criticises the way complicated opaque models inhibit imagination and creativity. "Too much detail for the sake of realism is confusing and self-defeating." He then gives a number of examples of systems that had to be abandoned because they "contain coding mysteries that produce counterintuitive, unexplained results."
My experiences with Stock and CHS scenarios with Manila and Singapore has just been to initiate your basic seige warfare. RHS and its supply sinks might last a bit longer than the CHS types as I've not gotten far enough into an RHS scenario to find out yet.
Send in enough troops that a counter-attack by the defenders can't dislodge them and just use bombardment attacks daily (so lots of artillery types help). Then use aircraft to reduce both the supply depots (port and/or airfield attacks) as well as using aircraft to reduce the numbers of troops (ground attack). This does 3 things...it disrupts the ground troops, disables squads, and uses supply at twice the rate just attacking the depots would as the LCUs attempt to repair their disablements.
Watch your combat reports and when it estimates you have about a 3:1 advantage in troops you are probably ready to start deliberate attacking.
Even against players that move everything to Singapore and Manila, I can usually go ahead and take Singapore by early to mid-March and Manila by late April. You just have to be patient and resist the urge to keep adding troops in to the attack...use those troops elsewhere, a player who has turtled in those 2 places are contained and not really a threat.
Just as a general rule. 4 divisions and 4 artillery rgts/btns are usually sufficient in my experience. The main thing is to get the bases cut off from resupply and wait out the supply sinks. They will reduce over time. One other thing you might need is a group of planes on ASW warfare to combat those players that try to resupply by submarine. The subs don't bring a lot of supply, but it can extend the length of time the bases will last.
This are just my personal experiences, other players may have different ways to go about it.