The set and rep scheme of today's workout is set on the lower end because you'll be lifting heavy weight to build a foundation of strength. If you're cruising through this workout without breaking a sweat, you're not doing it right.
Build up to a heavy weight and then gut it out for three brutal reps. You have three minutes of rest between each set, so make sure you're stacking the plates. The lengthy rest periods will allow you to recover a significant amount of strength, so you won't have to switch to a lighter weight or sacrifice your intensity.
Even though you're lifting heavy triples, don't push yourself to an all-out 3-rep max. Come close to failure, but don't lift so much that you sacrifice form. You're not trying to test exactly how strong you are at this moment. You're building strength every day.