You should really test your Assassin abilities by never having medicine on you. I played my last time like this and it actually makes you have to be a lot more careful and a lot more assassin-like. For example, if you had 10+ guys around you and you didn't have precision you could be in a spot of bother, especially if the borgia are varied. When stalking, you need to use the rooftops carefully, use groups, assassin recruits, distractions and all the sort. Granted you can use all this with medicine also it makes it a necessity when you can only heal on doctors after large missions. I was doing the machine gun mission and didn't have medicine, I was only 1 health/synchronisation point for about half the ride, was intense as hell.
Making it through the game easily will get you about a 30% sync when you complete the game.... Brotherhood atleast..... Each mission has unique things you need to do to complete them, and i dunno if you bothered, but lots of them are fucking nearly impossible to do lol.... let alone, the glyphs are confusing as fuck.... you cant destroy leonardo's machines by smashing x, and you cant kill Cesare by smashing x, he has to be hit in various ways, kicked, and then assassinated while his health is in recover mode lol.... To accomplish a 100% sync in Brotherhood, is not an easy task.... at all lol people pretend AC is the easiest shit around, but they arent even coming close to actually beating the game..... Sure, i could beat fucking Super mario bros in 10 mins with star road, but did i do anything?