Credit Card Churn Advice - 3 Cards over 4 Months

Hello CC churner experts,

I'm in the midst of pushing for a specific reward and trying to figure out if there is any benefit in waiting before my next credit card application. Here's my brief history
No other debts - always paid off CC's. Above threshold for all min income requirements.

Oct 2021 - ANZ FF applied and approved. Credit Score "Very good" => 798
Nov 2021 - Credit score "Very good" => 774
Dec 2021 - AMEX applied and approved. ANZ now ready to cancel. Credit score "Very good" => 770

I want to close my ANZ and debating if there's any benefit to wait till Jan to pickup St George/Westpac. I'll still be holding AMEX until at least late Jan. It's been awhile since I've done such a heavy churn so some risk of being rejected for my next card from what I gather. Because of the deal timelines, I can't really apply later than early Jan for St George/Westpac as they tend to take longer to credit points and it'll get riskier the longer I wait.

Bit of a toss up but happy to hear other people's experiences about holding multiple cards in a short amount of time. Or if you have any experience with St George/Westpac speed of crediting points too would be good!

Thanks!