If you're looking for advice I recommend joining the official Discord for strategy help: https://discord.gg/narutoen. They have a channel, with both player and staff input, and it's a lot quicker for specifics.

Generally: save coupons, learn the game. Aizen said a LOT of info, so I'd honestly learn the game before going for specific units and over learning power interfaces. I also strongly disagree with like half of the units he mentioned, but that is both preference and strategic approach.

Aizen touched on a lot of stuff that simply isn't relevant as a catch all and is stuff you should learn as you go rather than taking it as specifics. By ranking power interfaces, you're mismanaging power resources generally rather than seeing them as better return at certain points. (There's also just misinformation galore, but a lot can be chalked up to personal preference / experience...)

The only thing I truly agree with is to save coupons.