You can probably stick with that routine for a while, though I’d like to at least see some rep variation. You could make it a 4 week progression like this:
Week 1: 3 or 4 sets of 10 reps
Week 2: 4 sets of 8 reps
Week 3: 5 sets of 5 reps
Week 4: max effort – 5 reps, 2 reps, then as many sets of 1 rep as it takes you to reach a max effort
Week 5: repeat
I’d also like to see you throw in some stiff leg deadlifts or good mornings on Friday either before or after your lunges. Just 2 or 3 sets of 8-12 reps would be fine.