Not necessarily. Let's use Coriolis' specs as an example.
We'll ignore the Huge mount as it is a shared element.</ br> 1 Fixed Large Pulse Laser is 18.1 DPS</ br> 1 Fixed Medium Pulse Laser is 12.1 DPS</ br> 1 Fixed Small Pulse Laser is 7.9 DPS
2 FLPL + 2 FSPL = 52</ br> 4 FMPL = 48.4
The Mamba has a tiny bit more 'raw' DPS due to the way damage increases by mount sizes.