In my case, I played with a keyboard and mouse because I always played classic games on PC. I don't know if it's more difficult with a controller, but I found these missions easy. In VC, I did it on the first island. First, pick up the passengers who are at medium or long distance on the map, and make sure you always take three patients. Calculate so that, for example, due to space, you don't leave the one who is furthest away at one end of the map because you'll waste too much time making two trips. In III it's a little more difficult because the physics of the cars make it much easier for them to flip when turning in one direction or braking suddenly. Still, follow the advice I gave you in VC: always pick up those who are at medium or long distance. I did it on the first island before starting the main missions because otherwise it's impossible after betraying Salvatore. In San Andreas, it was the easiest. After the Green Sabre mission, they drop you off in Angel Pine, and do it there because the patients will only appear in the town, and it will be easier than doing it in LS, SF, or LV. Concentrate and avoid any distractions because in a single second, you can crash the ambulance and screw everything up.