FT-MT Missile warheads

I was just thinking about a comment someone raised (forgot who) about MT
missiles could (notice the COULD) use laser heads instead of nukes. This I
think is likely, due to the fact the nuke if making a direct contact (highly
unlikely) would vaporise any warship built, and a near miss would have most of
it`s effects mitigated by the ships sheilds, which don`t degrade MT missile
hits. I say this because for the sheilds human ships mount would have to have
a very high gauss field to effect direct fire partical weapons, and the earths
magnetic field is strong enought to redirect the high energy particals
released from the closest local nuclear reaction in our vicinaty. A ships
magnetic field wouldn`t be as powerful as the earths (of course), but they
would be very dense due to having a smaller volume to enclose, which should
have some effect on any nuke detonating close to a starship. A laser warhead,
on the other hand would only have to detonate close to the ship, and the
chance of some of the beams hitting (thinking of multipul emmiters from one
bomb) and some missing would also explain why the dammage would be randomised
(die roll) and a ship being able to survive. Another idea I had would be to
alter the dammage at different ranges from the ship targetted, to represent
the chance of more beams hitting at closer ranges. For example, at 3 mu=1D6, 2
mu=2D6, 1 mu=3D6.

Just another one of my hair brained ideas <G>.