Seems our PvP combat isn't as inaccurate as you think. Maybe everyone is just too used to normally PKing on OSRS where you're not usually fighting someone with 99 defence?

Equal bonuses
249/500
242/500
241/500
238/500
245/500

64 vs 32
78/100
76/100
72/100
75/100
74/100


This is nearly our current combat formula