trust me, going range based isn't a bad thing. I had a similar account to you named 'smug' sadly it got banned for botting but it's stats were:
20 attack
99 str
1 def
85 range
80 mage
69 hp
1 prayer.
I used many style of weapons to get the kill always with the cvl as the main KO weapon. One of my favirotes was
can i also suggest getting 90+ str. I know it takes time just go get like 500 zeals you will love it trust me.
dbolt - msb spec - cvl
or
simply knife to half hp and cvl.
^ can get expensive however.
just simply msb when they're half hp msb, as soon as your bow is raised for the first arrow switch to cvl. that should ko anyone.