I think you're reading too much in SophieX comments here. There are a few ways to skin a bear and you both agree that 40w tanks are not the sole tool to break through.
Yeah, you're probably right, sorry. It's hard for me to view things from a non-competitive mindset, so seeing people advocate for what I see as bad habits in a thread that's by a new player trying to get better kind of makes me a bit judgemental, but I shouldn't respond the way I did. I just want new players to become skilled enough to enjoy this great game, that's where I'm coming from at least.
To be sure, nearly anything can beat the AI. That being said, if new players take advice that beats the AI but is more difficult than playing optimally, then decide to go into multiplayer or try to do hard challenge runs where you need to play optimally to have a chance at success (many of the more niche achievements) they're going to have a bad time.
EDIT: After my most recent playthrough, I'm starting to understand more the position of players who handicap themselves on purpose. I did a run as the USA where I abused the Naval Treaty and the Homeland Defense Emergency Act along with some communist focuses to be on Total Mobilization with 0% consumer goods as the USA by October 1936, with Japan annexed before 1937. Democracies can use the Local Autonomy occupation policy, so Japan was at 100% compliance by 1940. I had 300 military factories by 1940, the build slots and infrastructure in the USA and Japan were capped out, and didn't need to invest into navy at all because I was democratic USA in the Allies with Japan already having been annexed, allowing me to have a massively ahead in tech air force and armored corps.
It was a very simple matter to completely steamroll AI Germany, with D-Day in France in 1941 with 20 40-width heavy tank/amtrac divisions after invading Italy slightly earlier and I was so overpowered that even building Heavy Fighters and Tactical bombers instead of the "meta" air force composition of FTR and CAS, I was pretty much invincible. It was so unfair that I didn't even have that much fun with it.