So on G1 your going to mass subs, then on R1 I’m going to counter with armor for the counter attack on Germany since your not reinforcing the lines. Then on UK1 I’m stocking up on Bombers so I can bomb Germany and Italy to the Stone Age.
If Britain builds Bombers, then you can go secure the seas around the United Kingdom easily, whereupon Britain will never be able to invade you. Since invasion is no longer a concern, you can then return the focus to crushing Russia.
G2: to my delight you built more German subs so I’ll just keep building Russian tanks and UK Bombers and possibly tech dice.
Why would I build more German Subs? I already have 8. At this point, Germany should probably switch to massing Infantry and Bombers. 7 Infantry and 2 Bombers is about right. The Bombers can assist on either the naval front or ground front. Bombers work well with Subs, because while they have half the durability, they can help in ground combat as well, and don’t expose themselves to counterattack to the same degree.
It just occurred to me that with a Sub/Bomber force, you will be killing Fighters with Bombers. !?
J1: If we’re playing '41 17 bucks is only gonna get you 2 subs, so I wouldn’t consider that a large fleet.
First turn, Japan should sink all of its IPCs into Research Chart 2. By the time it collects some real money on the following turn, it will probably have a tech, and it can mass appropriately. If they get Super Subs, Radar, or nothing, they should probably invest in some Subs to keep Americans away. If they get Improved Shipyards, they should crush the US with a more conventional fleet, and anything else they should focus on abusing their uber air force instead.
Even if you buy them that doesn’t force America into buying Destroyers. America can counter with subs just the same. While Japan is busy stocking up on subs to scatter around the Pacific, I’ll just buy some bombers and tech dice to help out the UK in crippling the German war machine.
Then Japan sinks the American fleet, and either invades West US or goes back to ignoring America and pounding Russia.
A lot of your criticism seems to revolve around the presumption that once a side starts massing Subs, they will continue to mass Subs forever and not react to enemy tactics. The Subs are a tool to deter and destroy navies and transports. If they have been deterred or destroyed, then you no longer need to be building Subs.