I will say, if you use feint and face down cards, it makes the air cover WAY worse. If you have to guess if each offense card needs a light or a heavy cover, because of face down cards or feint, then instead of matching your 1 point light aircovers to 2 point light strikes or 4 point heavy bombing, you now have to attach a 1 point light cover and a 2 point heavy cover to every aerospace attack to try and stop the one heavy bombing card. With the cheap feint thrown in, it forces a defending player to play nothing but air cover, and you simply cant have enough cover because of the bluff eating your cards.
So while I think a meta of face down cards could have been fun, the cards/feint are not priced for that mechanic. Its also unfun to see your heavy air cover guess wrong and go on a light strike, while your light air cover ineffectively goes to the heavy bombing/bluff, because of randomness beyond your control. Its like saying your intercept craft dont have radar and have to blindly blunder into enemy contact, instead of being functional air cover.
Imagine if you had to guess which mechsheet your gauss rifle was shooting, like all mech sheets were face down and you had to randomly pick a face down sheet. Oh, sorry, I know you wanted to intercept the atlas attacking you, but you randomly selected the locust, so you have to shoot it instead. Thats kinda how it feels to me.
Like, you can literally see a bomber literally flying in for a bombing run on a target, yet you cant just intercept it with your air cover, and have to attack some prop plane instead? I dont know... the cards just arnt priced for that kind of interaction, meaning its just all bad feelings in my experience.