Not sure I agree.

If I'm a trained covert assassin and I find myself in the middle of a 17th century-style naval combat involving Japanese vs. Portuguese marine technology, it seems what I ought to do is attempt to covertly board the enemy vessel and assassinate its captain. If I'm a trained covert assassin and I find myself in the middle of open field daylight desert island team combat against trained shock troops, it seems what I ought to do is run away and come back in about twelve hours and try again.

More generally, part of what a sufficiently trained combatant is taught to do is control the combat situation, rather than take it as a given.