The biggest strength of AC is moving around the city as you please, using the items/weapons at your disposal. The Leonardo missions warp you to these remote locations where it's basically point A to point B without being seen. There are no proper stealth mechanics like ducking so it really comes down to exploiting crap enemy AI to get by.
Just now for example I had to take down 2 couriers for an Assassination Contract mission. I hid in a group of people, used the poison dart on one of the couriers guards, big group stood by and watched, I walked through them and poisoned the courier and walked away without being noticed. Once he died the guards went on alert and on my way to the second courier I was spotted by 2 guards, I threw a smoke bomb and sprinted to a horse, ran down the second courier and assassinated him off the horse. Than me and bystanders took out the rest of his guards in a brawl. Stuff like this would never happen in the Leo missions, at least not in the ones I played [first 3]
Just now for example I had to take down 2 couriers for an Assassination Contract mission. I hid in a group of people, used the poison dart on one of the couriers guards, big group stood by and watched, I walked through them and poisoned the courier and walked away without being noticed. Once he died the guards went on alert and on my way to the second courier I was spotted by 2 guards, I threw a smoke bomb and sprinted to a horse, ran down the second courier and assassinated him off the horse. Than me and bystanders took out the rest of his guards in a brawl. Stuff like this would never happen in the Leo missions, at least not in the ones I played [first 3]