I know that the usual way of using two -bogh clauses on a noun is by joining them with 'ej:

HoHbogh 'ej Qaw'bogh nuH
weapon which kills and destroys

But is there any rule which is actually being broken if we wrote the above without the 'ej?

HoHbogh Qaw'bogh nuH
weapon which kills which destroys

Why would writing something like this be wrong?

~ Dana'an
woe unto you scribes 
and pharisees hypocrites