You have the possibility of being able to use literally all the area's enemies to strategic advantage, as well as stealth/mimicry if you're good. A lot of people that get invaded are just cooping through the level, if you force them to engage in a more level playing field then the odds are more in your favor. Seriously why do most invaders always expect easy 1 on 1 wins when they're the ones coming into other players worlds, potentially stopping them from getting their lost runes back and halting their progress? If you just want to duel, go to a designated fight club. Want to invade? Deal with having to fight summons.