That's the problem though, the supply/durability system described here is nothing like the system used in Dota 2 and CSGO. If they straight-up copied Valve's model that would be amazing. Paying for cosmetic items is totally legit, because it doesn't give you additional gameplay options and it's totally not necessary to do if you just want to play the game competitively. What isn't legit is paying for more gameplay options (different topic though) or paying to continue using your items over time.
If it's limited to only dropped items, it turns off the large number of people who play for that carrot-and-stick incentive of getting a drop after the game. Just look at the anger over the War Spoils system, and the backlash against Valve recently for their changes to the Dota 2 drop system. That's the best-case scenario, and it's still a major negative for a large portion of the community.
You cannot implement Dota2 or CS:GO model into Coh2.
Dota2 is a game aiming for fun in its level of execution, calls, dialogues, heroes are mostly fun. And from that fun, you can take a lot of freedom to design cosmetics, dialogues, calls etc... and sell it, you are just limited by 2 facts: your imagination and the frame decided by Valve.
CS:GO is also aiming for fun and personalization, you can also play with audio, weapon skin and model skins, those are really visible and gives a personification of your pixel character.
Coh2. Coh2 is fun as well, for sure that is part of his objective but in a clear different manner and for sure not in a visual or auditive one. You cannot change you Panther skin to pink with blue bubble because it is fun, you cannot change voices by stupid one because its fun. The frame is clearly limited to a "realistic" visualization and immersion. People find their fun in that realism and its execution with the game engine. You cannot decided to design flying wingmen grenadiers squad in all statistics equal to normal one's but visually funnier.
So basing your economic model on skin and decay... that's going to last a couple of months before all realistic skins and possible voicing are available onshop, and next what?
Coh2 doesn't make you control a single character you can personify but an army, a commander and here is the personification. And it goes in that direction, the one COHO was taking in his time. You select your preferred army, and you design your commander in a dedicated frame. And because your commander cannot be personified you need to found another way to do it. And it goes to abilities and monetize it with economic transactions.