You can use Programs to create the cadence you want, but the lead will continue through the programs in the EP based on the cadence, not based on whether they completed the flow in the previous program.
Another option is that you add the first email to the program that adds the leads to EP. so the flow would be 1) Add to engagement program, 2) Send email. Then they would pick up on the next cadence but keep in mind that might be 2 weeks or 1 day, depending on when they get added.
Hope this helps.