Send the same email delivery (only 1 copy of the email) to targets split out with Waits?

Is it possible to send the same version of an email as only 1 copy of the file (not duplicates) to split target groups each with a wait - I guess basically a Drip Campaign? We've only been able to make it work with using multiple copies of the same email, and this is not exactly optimal. What we are doing is targeting based on the last time a customer opened an email from us, then we separate them out into different groups and send to each group with a wait - ie, send to 30 day openers immediately, send to 60 day openers after an hour, send to 90 day openers after 2 hours, etc. We want to be able to just use 1 file, rather than 10. (as seen below:)

We've done some simple testing with waits and sending the same email file that worked with a very simple list of a few people, but we can not get the below workflow to work with our actual very large list of 100s of thousands:

Any help is greatly appreciated! Thanks!