To some extent you may be right.... but I am trying to build economically. Maybe I will post a screenshot of what I manage later, I'm still fiddling with designs. but after the first run of designs, and then a second set of more budget designs I'm still struggling to see how to stretch the money much further.
For example right now the cheapest BB design I have is about 14 million, and it's all around mediocre. Maybe I could rebuild the ones I used in the 1910 campaign (btw it would be nice to be able to save the designs from Campaigns as well) which were around 11-13 million IIRC and were good ships in that campaign but might be undergunned with only 12" guns in the 1920 campaign. so let's say I build 3 of these for 35 million.
Then building a CA around the 9" or 10" guns, 25 kts, lowest tonnage, medium bulkheads, medium range, No barbette citadel or torp protection upgrades, no engine upgrades, no reloading or ammo upgrades, the most basic rangefinder etc and you're still somewhere close to 10 million. Putting basic versions of some of the upgrades in brings it to maybe 11-11.5 mill. That also isnt even using up the tonnage limit of the smallest tonnage version of the hull. lets say I build 4 of these for 40 million.
Thats 75 of 90 million spent for 3 BBs and 4 barebones CAs. That leaves 25 million for CLs and DDs. Maybe you can build equally barebones CLs for around 6 million and DDs for around 2.5 or 3 (right now my CLs are coming out to 8 and DDs at 4 but they could definitely be made cheaper). So that gives me some mix of maybe 2 or 3 CL's and 4 or 5 DD's. I also have built 0 BC's.
In summary building mostly very very basic ships: 3BB, 4 CA, 2 CL, 5 DD
That gives me those ships vs the AI's current 5 BB, 3 BC, 11 CA, 17 CL, & 24 DD
From my experience in the other campaigns the AIs ships while sometimes poorly built and sometimes not, usually cost more than my designs, and also come with trained crews which I don't get either.
Edit: I checked and in this campaign the AI's CL's cost 15.9 million. At 17 CL'S thats 272 million just in CL's...
DD's cost 4.4 mill each. x 24 = 106 mill
Not that the campaign isn't winnable, it just makes the gameplay fairly unrealistic. In the 1910 campaign I basically built a similar ratio of ships as above to the enemy (although in 1910 I could build budget, but still pretty decent ships) and quickly lost 60% of transports because I got blockaded and didnt have enough presence to protect convoys I guess. But I was able to defeat their ships in almost every single battle without losses due to weak AI designs and bad tactics until there was a revolt from all the negative prestige I guess. The AIs poor ship design was RNG as in a previous campaign they had built the same amount of much more dangerous ships which would have made things more difficult.
If you are able to come up with cheaper designs that aren't just totally barebones Id be interested to know how.