SMN is easy due to how it's rotations work, as you have your Bahamut/Phoenix stage, and between them 3 largely interchangeable blocks with the different summons, which don't necessarily need to be used in a specific order. The biggest challenge generally is finding the safest moment to use Ifrit, which involves being able to stand still for about 5 seconds to cast Ruby Rite twice, and going to melee range for a short moment.