I wholeheartedly agree OP. Many countries have already made laws on sexual crimes more equal by doing away with the term 'rape' and expanding the definition of sexual assault to include all forms of sexual violence (I believe Canada is one of these countries).
I think this is definitely a good thing. The term 'rape' provokes a stronger emotional response than 'sexual assault', thus when someone is convicted of (or even just charged with) sexual assault, the public is generally not going to respond as negatively towards this person than if they were convicted of rape.
The argument "well women can be convicted of sexual assault, which can carry the same sentence as rape, so we don't need to do anything" reminds me of an argument used by the anti-gay marriage; "a civil partnership is basically the same thing as marriage, why can't you be happy with that?" The latter argument is generally considered to be poor and we shouldn't be happy with the idea of 'the same but different' when it comes to social unions, and yet the analogous argument when it comes to sexual violence law is considered to be acceptable, or at least not questioned to the extent.