DSII Ideas for Bugs

I happened upon a whole mess load of epic scale tyranid models that I
want 
to use in DSII.  The big bugs have giant claws that would easily be able
to 
rip through a tank, but I'm not sure how to incorporate this into the 
existing DSII rules (unless I'm missing something).  I was thinking of 
giving them an extra DFFG-1 or 2, maybe a multi-barrell 1 to keep the
range 
really short, to approximate the effect of the claws lashing out at a
close 
vehicle, and an APFC for the effect vs troops.	What do you think?  Any 
other ideas?

I also have a bunch of Ork tanks with crazy claws and giant rollers and 
such... I figured an APFC on those would approximate their effects vs. 
troops.  Sound about right?

Thanks.

Fred