While I generally agree, I think this is way out of scope for CoH2. It would mean reworking the whole pricing and balance for basically every unit and ability in the game.
Also it depends on what kind of game you want, because at the moment a normal game lasts between 20-50 minutes. Slowing everything down would mean that games would regularly reach the 1 hour mark and more and not everyone wants to play these type of games.
I agree with you that changing the pace of the game would generally create endless other balance issues, including making the power spikes created by individual units and factions even more obvious and more difficult to counter/handle. Overall, this is an irresponsible balance suggestion.
Power spikes would be even more difficult to have appropriate timed solutions, and people would be locked to bases fairly quickly if they do a single mistake, as they have no resources left. It would be such a massive change that everything in the game would have to be re-evaluated and modified; and even if we assume this goes well, the game would be totally different after that and certainly not CoH2 anymore.
Also, the game works best when medium and heavy vehicles are buildable; delaying them would make the game more boring and very and highly predictable.