during your workout:
do many sets of as many pullups as you can....but not numerous sets in a row.
do a set. do another exercise.
come back...do another set....do another exercise.
by the end of your workout, you'll have exerted max effort on those sets of pullups without diminishing your effort or wasting your time resting up.
example:
1 set pullups max
3 sets of bench press
1 set pullups max
4 sets incline dbell press
1 set pullups max
3 sets crunches
and so on and so forth.
you'll get more workload, less fatigue, more effort.