Not me.
Advantages / Disadvantages
There are two main advantages/ disadvantages.
Heroes
Without the proper heroes you will always be at a disadvantage.
With the proper heroes you will have an advantage.
Hero potential
Without heroes at maximum costume, and X*+20, with maximum level troops, you will always be at a disadvantage.
With maximum potential heroes you will have an advantage.
Skill
Strategy
Even with all the above ( proper available heroes at maximum potential ) you still need to choose the correct team for attacking a defense. This is where knowledge, and skill first enter the situation.
Tactics
Even with all the above, you still need to choose what shields/ tiles to match, and when to use each special skill. This is where knowledge, and skill, also enter the situation.
RNG
RNG Special / Talents
If your team contains RNG heroes ( Wu Kong, Danzaburo, 5/5 Revive, 5/5 Evade, 5/5 Withstand, etc. ). This is where the majority of RNG enters the situation.
Boards
Without a decent sequence of boards you are at a disadvantage. ( starting board plus first 24 moves, 80% chance for rainbow team with all very fast heroes to 25% chance for mono team with all slow heroes ). This is the next biggest RNG factor.
Single target special skill
Special skills with a single target can have a variability of plus, or minus, 50% to damage ( or more. the exact damage formula currently unknown ). This is where RNG also significantly impacts the situation.
Combo chains
Combo chains ( Combo 3+ ) are the next biggest RNG.
Critical hits
Critical hits are the next biggest RNG.
Normal damage
Normal/ matching/ tile damage has the least amount of RNG since matches require at least 3x shields/ tiles.
Notes
See Also
([Guide, Wiki, Tactics] Placement of heroes when attacking - titans, bosses, raids, Jabberwocky, Gato)
([Essay] Please remove 1* and 2* Tourneys, I have already said good bye)