As a general addition, is there a score that people feel is "too low" to do an AOR?

As a young person (26), my AAoA is quite low as during my first AOR (December) I went from two active credit cards to seven which has had an obvious negative impact on my score. I went from 780 to 705 (CreditKarma, lol). No negative inquiries, 0-4% utilization, etc.

I have no need for nonsecured debt (own home outright, already have car loans) so I don't need perfect credit, but also don't want to apply too soon and end up with a string of denials.

CreditKarma currently sits at 720, which obviously isn't perfect. Just wondering if it is too low to try to squeeze another three cards in my wallet in a month or so that can better handle higher MS (thinking SPG, Southwest, Citi Reserve... one from each major issuer. I know Barclays would be instant denial on me most likely) .