Percentage for 3x3 Lift?

Me and the guys are setting up a program where we are lifting every other day focusing on gaining strength in the main lifts that will look like this:

Squat 3x5 Pros
SLDL 3x8
Prowler Walks


Bench 3x5 Pros
Press 3x3
Chins 5x10


Squat 3x3
Deadlift 5 Pros
Prowler Walks


Press 5 Pros
Bench 3x3
DB Rows



What percentage would you recommend for 3x3 sets and how much warm up for 3x3 press and bench.

We are in our late 50s and early 60s and will be doing this for about 3 cycles.

I would do Second Set Last percentages.