Do you know what you N1 should be on any given takeoff, or do you trust the EPR?
Not sure about others, but my T/O data cards are written as follows (for this very reason).
2.15 2.17 2.15 || 99%
2.00 2.02 2.00 || 94%
The PNF will trim the throttles out to the desired EPR then the Engineer will fine tune the the throttles on the roll taking into account all indications. Though, most of the times we leave ourselves enough takeoff margin where setting all 3 slightly low will still leave us room to spare.