I tried fixing the US build priorities in the scripts, specifically carriers, changed all of the 10's to 40's or 50's...
Just checked my saves (by loading as Allies). Most ships apparently come in via scripts, because as of Jan '43 there's exactly 2 ships in the US queue, a carrier (which iirc is one I put in there) and a light cruiser. But a good chunk of the ones which are built keep showing up in the Atlantic, and the AI apparently never uses the Panama Canal...
1943 probably set a record for the most warships built by a single country in a single year in the history of naval warfare, note.
Anyway, The Battle of the Coral Sea (early '43) was a total disaster for the USN: 3 CV's (for some reason Hornet didn't join the armada, stayed in LA the entire time), 3 BB's, 5 cruisers, 2 DD's, all toast within 2 turns [I had 6 CV's of my own, destined to have 12 by the end of '44, which is probably too many given that I am starting to run out of escorts]. I lost one CA, tho had to LOL at the lone 3 point tank which used all of the distractions to go amphibious in his port with my ships all around, couldn't spare a single strike on him, he took one of my bases the next turn...
Checked in spring '44, and only then were the Essexes in the queue-to come (as in my last run-through) from mid-44 thru the end of 45 (tho my slightly failing eyes undoubtedly deceived me when I saw 2 due in 1948!). By that time their Pacific fleet had 2 CV's, 2 CVL's, 2 BB's, 2 cruisers, and one sub (worthless because the AI doesn't invest in sub tech, at all, have sunk 4 total, incl. British). Again my guess is that it can't buy an expensive carrier (or battleship, nope no Iowas on the way either) if it has already spent too much MPP's that turn (tho as said in my previous post upthread there is apparently a toggle for the AI to ignore that, if I am inferring the script correctly). A year later another US fleet joins them (same area), scratch 2 more flattops...
As I suspected, the AI only builds them after it has built everything else, by which time the Pacific is a Japanese lake. You'll simply have to script all of those CV's it would appear, requiring a counterbalancing by eliminating most other AI ship freebies.
Meanhoo the European theatre was more balanced, endless Western Allied landings, which my tanks keep killing, but that of course sucks all of the momentum from the Russian front, tho the Caucasus, Stalingrad, and Moscow are all mine now. My sub fleet is nonexistent, and only now do I plan to marshal all of my fighters to regain air superiority over France. Had a bit of fun letting the Italians rampage thru central Africa. [China is now a rump state note, tho I am only now knocking on the doors of India]