Suicide Fighters

In our latest campaign one of the players plays a race which has
fanatical loyalty to the Emperor and he asked me (the umpire) if he
could develop suicide fighters.

I have allowed this as follows

A Lance Group (suicide fighters or perhaps unmanned drones) moves as
normal fighters with a speed of 18cm. They cost 38 points per group and
each group has only 3 ships. On the CV they take up a whole fighter bay
and are packed with explosives etc. rather than weapons

On the go they attack, if they survive all the defensive fire they
impact causing 2d6 of damage as with a nuke missile with a bonus of a
needle throw on the target vessel.

If attacked by enemy fighter groups they are defenceless! They have no
weaponry or combat ability apart from ramming their intended target
which they must reach to cause detonation. (hence the faster speed)

If shot down within 6" of their actual target they explode causing 1
d4+1 damage  to that ship only.

Any comments or suggestions would be appreciated

John Bennett