99/2=48.5 x3 = 145.5 145.5-99= 46.5 attack level you can get without raising combat if you have 99 strength
To put this in easier to understand terms
So it will in fact raise your combat.
As for the question, G Maul is much more effective as you can hit 3 times instantly then 1 more delayed. Claws are easier to use, but the hits are slower so they have more time to realise what is happening and eat.
The Gmaul is definitely my favorite. In my times of PK'ing, I haven't had a lot of problems with the Gmaul as a pure that I have had with the Dragon claws. The Dragon claws, in some cases, can be deadly but the Gmaul seems to put in greater hits.
Claws are a lot easier to use but a claw spec can be seen coming from a mile away and can easily give them enough time to tele or tank with P necks. When you get good hits in with a gmaul your opponent is screwed.
I suggest attacking with a dark bow first without spec, use the gmail specs and then hit them with a corrupt statius warhammer if they are still alive.