Rpm is key regarding the tail. It's not always a function of blade size, more importantly speed. The 96s will hold on a 556 e5 with any motor and collective setting, as long as they are near 10k rpm and the servo speed/gain is optimized. 4.0 x 2500rpm is the recommended setup, so at 2300 you'd only need the 4.5 ratio or 106s, not both. Hope this helps.