I've always had better trails with 3 blades than 4, regardless where they were hit. Almost every 4-blade trail was worse than it should have been, and have no idea why.
It is such an individual experience with each shot because I have had red carpets with both and hardly any blood with both. The shot placement is so crucial in the blood trail that the blade count is mute. I would find a head you like and see if it likes the bow. All Broadheads are made to cut but not all Broadheads fly true out of every setup. I have shot four blades for the past 5-6 years and if I do my part the deer are easy to track.