Is it possible some bows just tune easier than others
Yes it is.
Some bows are easy to tune and then some are a real pain in the behind to tune but all bows are tunable.
I like the sound of cut on contact and have plenty of time and with right help I am going to try to get the 3 tunes together and go with c.o.c b/h's!
Well IMHO they are the best but you must pick a good head one that has thick blades, I personally wont go below .040 blade thickness, have had thinner blades bend and break when they hit a solid bone but the thick ones will just smash through.
I am not anti Mech I have used them in the past, but a lot of people think they dont have to tune their bow and use mech's as a band aid for their untuned bow.