If they don't have one, they never engage the enemy MS when attacking.
As long as they have a bigger natural strike then the biggest natural def they can hit anyone.
If they just get a large covert and large strike, with the limitation for poli kills it means there is actually no need for them ever to keep a def themselves.
with a 0 def means it also renders the enemies MS strike useless as well.
So to this end, it seems to make sense never to build one

















