MC Phono preamp gains

If an MC phono preamp supports 45dB to 70dB, then would it work just like MM phono preamp if its gain is set at 45dB?
If that's the case, those phono preamps which support both MM and MC can essentially work as two MM inputs, right?

I am looking for a phono preamp that supports two MM inputs. I already have an SUT for my MC cartridges, so an MC input is not needed, but there exits very few phono preamps which support two MM inputs. So, I wonder if I can use those phono preamps that support both MM and MC as two MM input phono by setting the MC gain to the lowest (45dB).